256004344520 has 32 divisors (see below), whose sum is σ = 576096849720. Its totient is φ = 102386257920.

The previous prime is 256004344489. The next prime is 256004344529. The reversal of 256004344520 is 25443400652.

It can be written as a sum of positive squares in 4 ways, for example, as 209941741636 + 46062602884 = 458194^2 + 214622^2 .

It is a super-2 number, since 2×256004344520² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (256004344529) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 213977 + ... + 746856.

Almost surely, 2^256004344520 is an apocalyptic number.

256004344520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

256004344520 is an abundant number, since it is smaller than the sum of its proper divisors (320092505200).

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

256004344520 is a wasteful number, since it uses less digits than its factorization.

256004344520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 967505 (or 967501 counting only the distinct ones).

The product of its (nonzero) digits is 115200, while the sum is 35.

The spelling of 256004344520 in words is "two hundred fifty-six billion, four million, three hundred forty-four thousand, five hundred twenty".