256528064520 has 384 divisors, whose sum is σ = 1080120787200. Its totient is φ = 51275814912.

The previous prime is 256528064509. The next prime is 256528064531. The reversal of 256528064520 is 25460825652.

It is a happy number.

256528064520 is a `hidden beast` number, since 2 + 5 + 65 + 2 + 8 + 0 + 64 + 520 = 666.

It is an interprime number because it is at equal distance from previous prime (256528064509) and next prime (256528064531).

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 416374 + ... + 828506.

It is an arithmetic number, because the mean of its divisors is an integer number (2812814550).

Almost surely, 2^256528064520 is an apocalyptic number.

256528064520 is a gapful number since it is divisible by the number (20) 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 256528064520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (540060393600).

256528064520 is an abundant number, since it is smaller than the sum of its proper divisors (823592722680).

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

256528064520 is a wasteful number, since it uses less digits than its factorization.

256528064520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 412189 (or 412182 counting only the distinct ones).

The product of its (nonzero) digits is 1152000, while the sum is 45.

The spelling of 256528064520 in words is "two hundred fifty-six billion, five hundred twenty-eight million, sixty-four thousand, five hundred twenty".