565499981 has 2 divisors, whose sum is σ = 565499982. Its totient is φ = 565499980.

The previous prime is 565499953. The next prime is 565500007. The reversal of 565499981 is 189994565.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 494350756 + 71149225 = 22234^2 + 8435^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-565499981 is a prime.

It is a super-2 number, since 2×565499981² = 639580457022000722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (565499281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 282749990 + 282749991.

It is an arithmetic number, because the mean of its divisors is an integer number (282749991).

Almost surely, 2^565499981 is an apocalyptic number.

It is an amenable number.

565499981 is a deficient number, since it is larger than the sum of its proper divisors (1).

565499981 is an equidigital number, since it uses as much as digits as its factorization.

565499981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3499200, while the sum is 56.

The square root of 565499981 is about 23780.2435016969. The cubic root of 565499981 is about 826.9467249566.

The spelling of 565499981 in words is "five hundred sixty-five million, four hundred ninety-nine thousand, nine hundred eighty-one".