2561531264 has 32 divisors (see below), whose sum is σ = 5105803800. Its totient is φ = 1280074752.

The previous prime is 2561531257. The next prime is 2561531267. The reversal of 2561531264 is 4621351652.

It is a tau number, because it is divible by the number of its divisors (32).

It is a super-2 number, since 2×2561531264² = 13122884832898875392, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2561531267) 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, 300047 + ... + 308465.

Almost surely, 2^2561531264 is an apocalyptic number.

It is an amenable number.

2561531264 is a deficient number, since it is larger than the sum of its proper divisors (2544272536).

2561531264 is an equidigital number, since it uses as much as digits as its factorization.

2561531264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10810 (or 10798 counting only the distinct ones).

The product of its digits is 43200, while the sum is 35.

The square root of 2561531264 is about 50611.5724316090. The cubic root of 2561531264 is about 1368.2534555404.

The spelling of 2561531264 in words is "two billion, five hundred sixty-one million, five hundred thirty-one thousand, two hundred sixty-four".