256640031357526 has 4 divisors (see below), whose sum is σ = 384960047036292. Its totient is φ = 128320015678762.

The previous prime is 256640031357449. The next prime is 256640031357553. The reversal of 256640031357526 is 625753130046652.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64160007839380 + ... + 64160007839383.

It is an arithmetic number, because the mean of its divisors is an integer number (96240011759073).

Almost surely, 2^{256640031357526} is an apocalyptic number.

256640031357526 is a deficient number, since it is larger than the sum of its proper divisors (128320015678766).

256640031357526 is a wasteful number, since it uses less digits than its factorization.

256640031357526 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128320015678765.

The product of its (nonzero) digits is 27216000, while the sum is 55.

The spelling of 256640031357526 in words is "two hundred fifty-six trillion, six hundred forty billion, thirty-one million, three hundred fifty-seven thousand, five hundred twenty-six".