256521514140261 has 12 divisors (see below), whose sum is σ = 370852996999680. Its totient is φ = 170865763828200.

The previous prime is 256521514140257. The next prime is 256521514140449. The reversal of 256521514140261 is 162041415125652.

256521514140261 is a `hidden beast` number, since 2 + 5 + 6 + 52 + 151 + 41 + 402 + 6 + 1 = 666.

It is not a de Polignac number, because 256521514140261 - 2² = 256521514140257 is a prime.

It is a super-2 number, since 2×256521514140261² (a number of 30 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256521514145261) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12381566731 + ... + 12381587448.

It is an arithmetic number, because the mean of its divisors is an integer number (30904416416640).

Almost surely, 2^{256521514140261} is an apocalyptic number.

It is an amenable number.

256521514140261 is a deficient number, since it is larger than the sum of its proper divisors (114331482859419).

256521514140261 is a wasteful number, since it uses less digits than its factorization.

256521514140261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24763155336 (or 24763155333 counting only the distinct ones).

The product of its (nonzero) digits is 576000, while the sum is 45.

The spelling of 256521514140261 in words is "two hundred fifty-six trillion, five hundred twenty-one billion, five hundred fourteen million, one hundred forty thousand, two hundred sixty-one".