256520221001523 has 6 divisors (see below), whose sum is σ = 370529208113324. Its totient is φ = 171013480667676.

The previous prime is 256520221001489. The next prime is 256520221001599. The reversal of 256520221001523 is 325100122025652.

256520221001523 is a `hidden beast` number, since 2 + 5 + 6 + 5 + 2 + 0 + 22 + 100 + 1 + 523 = 666.

256520221001523 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 256520221001523 - 2⁸ = 256520221001267 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256520221001323) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 14251123388965 + ... + 14251123388982.

Almost surely, 2^{256520221001523} is an apocalyptic number.

256520221001523 is a deficient number, since it is larger than the sum of its proper divisors (114008987111801).

256520221001523 is a wasteful number, since it uses less digits than its factorization.

256520221001523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28502246777953 (or 28502246777950 counting only the distinct ones).

The product of its (nonzero) digits is 72000, while the sum is 36.

The spelling of 256520221001523 in words is "two hundred fifty-six trillion, five hundred twenty billion, two hundred twenty-one million, one thousand, five hundred twenty-three".