256772660406520 has 32 divisors (see below), whose sum is σ = 611723102734800. Its totient is φ = 96667354505728.

The previous prime is 256772660406517. The next prime is 256772660406553. The reversal of 256772660406520 is 25604066277652.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 188803426090 + ... + 188803427449.

Almost surely, 2^{256772660406520} is an apocalyptic number.

256772660406520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

256772660406520 is an abundant number, since it is smaller than the sum of its proper divisors (354950442328280).

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

256772660406520 is a wasteful number, since it uses less digits than its factorization.

256772660406520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 377606853567 (or 377606853563 counting only the distinct ones).

The product of its (nonzero) digits is 50803200, while the sum is 58.

The spelling of 256772660406520 in words is "two hundred fifty-six trillion, seven hundred seventy-two billion, six hundred sixty million, four hundred six thousand, five hundred twenty".