256121253544 has 48 divisors (see below), whose sum is σ = 547378473600. Its totient is φ = 111988229184.

The previous prime is 256121253541. The next prime is 256121253593. The reversal of 256121253544 is 445352121652.

It is a junction number, because it is equal to n+sod(n) for n = 256121253497 and 256121253506.

It is not an unprimeable number, because it can be changed into a prime (256121253541) 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, 4959544 + ... + 5010919.

It is an arithmetic number, because the mean of its divisors is an integer number (11403718200).

Almost surely, 2^256121253544 is an apocalyptic number.

It is an amenable number.

256121253544 is an abundant number, since it is smaller than the sum of its proper divisors (291257220056).

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

256121253544 is a wasteful number, since it uses less digits than its factorization.

256121253544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9970514 (or 9970497 counting only the distinct ones).

The product of its digits is 288000, while the sum is 40.

The spelling of 256121253544 in words is "two hundred fifty-six billion, one hundred twenty-one million, two hundred fifty-three thousand, five hundred forty-four".