42561565 has 4 divisors (see below), whose sum is σ = 51073884. Its totient is φ = 34049248.

The previous prime is 42561551. The next prime is 42561587. The reversal of 42561565 is 56516524.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 11792356 + 30769209 = 3434^2 + 5547^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42561565 is a prime.

It is a super-2 number, since 2×42561565² = 3622973630498450, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 42561565.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4256152 + ... + 4256161.

It is an arithmetic number, because the mean of its divisors is an integer number (12768471).

Almost surely, 2^42561565 is an apocalyptic number.

It is an amenable number.

42561565 is a deficient number, since it is larger than the sum of its proper divisors (8512319).

42561565 is an equidigital number, since it uses as much as digits as its factorization.

42561565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8512318.

The product of its digits is 36000, while the sum is 34.

The square root of 42561565 is about 6523.9225164007. The cubic root of 42561565 is about 349.1450288449.

The spelling of 42561565 in words is "forty-two million, five hundred sixty-one thousand, five hundred sixty-five".