256521125652 has 192 divisors, whose sum is σ = 677353635840. Its totient is φ = 74876659200.

The previous prime is 256521125647. The next prime is 256521125681.

It is a happy number.

256521125652 is nontrivially palindromic in base 10.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 235989453 + ... + 235990539.

It is an arithmetic number, because the mean of its divisors is an integer number (3527883520).

Almost surely, 2^256521125652 is an apocalyptic number.

256521125652 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 256521125652, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (338676817920).

256521125652 is an abundant number, since it is smaller than the sum of its proper divisors (420832510188).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

256521125652 is a wasteful number, since it uses less digits than its factorization.

256521125652 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1582 (or 1580 counting only the distinct ones).

The product of its digits is 360000, while the sum is 42.

The spelling of 256521125652 in words is "two hundred fifty-six billion, five hundred twenty-one million, one hundred twenty-five thousand, six hundred fifty-two".