I have a BigDecimal variable
BigDecimal x = new BigDecimal(\"5521.0000000001\");
Formula:
x = x.add(new BigDecimal(\"-1\")
To get a String representation of the BigDecimal without the exponent part, you can use
BigDecimal.toPlainString(). In your example:
BigDecimal x = new BigDecimal("5521.0000000001");
x = x.add(new BigDecimal("-1").
multiply(x.divideToIntegralValue(new BigDecimal("1.0"))));
System.out.println(x.toPlainString());
prints
0.0000000001