2561651431256 has 16 divisors (see below), whose sum is σ = 4803180557400. Its totient is φ = 1280803282624.

The previous prime is 2561651431249. The next prime is 2561651431267. The reversal of 2561651431256 is 6521341561652.

It is a happy number.

2561651431256 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 2561651431256.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2313770 + ... + 3236793.

Almost surely, 2^{2561651431256} is an apocalyptic number.

It is an amenable number.

2561651431256 is a deficient number, since it is larger than the sum of its proper divisors (2241529126144).

2561651431256 is a wasteful number, since it uses less digits than its factorization.

2561651431256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5608258 (or 5608254 counting only the distinct ones).

The product of its digits is 1296000, while the sum is 47.

The spelling of 2561651431256 in words is "two trillion, five hundred sixty-one billion, six hundred fifty-one million, four hundred thirty-one thousand, two hundred fifty-six".