256511554673506 has 16 divisors (see below), whose sum is σ = 419781713364288. Its totient is φ = 116586290940400.

The previous prime is 256511554673497. The next prime is 256511554673527. The reversal of 256511554673506 is 605376455115652.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 493247950 + ... + 493767721.

It is an arithmetic number, because the mean of its divisors is an integer number (26236357085268).

Almost surely, 2^{256511554673506} is an apocalyptic number.

256511554673506 is a deficient number, since it is larger than the sum of its proper divisors (163270158690782).

256511554673506 is a wasteful number, since it uses less digits than its factorization.

256511554673506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 987027497.

The product of its (nonzero) digits is 113400000, while the sum is 61.

The spelling of 256511554673506 in words is "two hundred fifty-six trillion, five hundred eleven billion, five hundred fifty-four million, six hundred seventy-three thousand, five hundred six".