565681 has 4 divisors (see below), whose sum is σ = 574192. Its totient is φ = 557172.

The previous prime is 565667. The next prime is 565723. The reversal of 565681 is 186565.

565681 = T₉₅ + T₉₆ + ... + T₁₆₁.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 186565 = 5 ⋅37313.

It is not a de Polignac number, because 565681 - 2⁷ = 565553 is a prime.

It is a super-2 number, since 2×565681² = 639989987522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (565651) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4155 + ... + 4288.

It is an arithmetic number, because the mean of its divisors is an integer number (143548).

2⁵⁶⁵⁶⁸¹ is an apocalyptic number.

It is an amenable number.

565681 is a deficient number, since it is larger than the sum of its proper divisors (8511).

565681 is an equidigital number, since it uses as much as digits as its factorization.

565681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8510.

The product of its digits is 7200, while the sum is 31.

The square root of 565681 is about 752.1176769629. The cubic root of 565681 is about 82.7034951956.

The spelling of 565681 in words is "five hundred sixty-five thousand, six hundred eighty-one".