265206645634561 has 16 divisors (see below), whose sum is σ = 271358655361920. Its totient is φ = 259097705568000.

The previous prime is 265206645634481. The next prime is 265206645634583. The reversal of 265206645634561 is 165436546602562.

It is a cyclic number.

It is not a de Polignac number, because 265206645634561 - 2³⁷ = 265069206681089 is a prime.

It is a super-2 number, since 2×265206645634561² (a number of 30 digits) 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 265206645634561.

It is not an unprimeable number, because it can be changed into a prime (265206645634061) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 47830300 + ... + 53086258.

It is an arithmetic number, because the mean of its divisors is an integer number (16959915960120).

Almost surely, 2^{265206645634561} is an apocalyptic number.

It is an amenable number.

265206645634561 is a deficient number, since it is larger than the sum of its proper divisors (6152009727359).

265206645634561 is a wasteful number, since it uses less digits than its factorization.

265206645634561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5260056.

The product of its (nonzero) digits is 186624000, while the sum is 61.

The spelling of 265206645634561 in words is "two hundred sixty-five trillion, two hundred six billion, six hundred forty-five million, six hundred thirty-four thousand, five hundred sixty-one".