521378750664 has 48 divisors (see below), whose sum is σ = 1413035566800. Its totient is φ = 173673764064.

The previous prime is 521378750647. The next prime is 521378750677. The reversal of 521378750664 is 466057873125.

521378750664 is a `hidden beast` number, since 5 + 2 + 1 + 3 + 78 + 7 + 506 + 64 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 521378750664.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2376574 + ... + 2586669.

It is an arithmetic number, because the mean of its divisors is an integer number (29438240975).

Almost surely, 2^521378750664 is an apocalyptic number.

It is an amenable number.

521378750664 is an abundant number, since it is smaller than the sum of its proper divisors (891656816136).

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

521378750664 is a wasteful number, since it uses less digits than its factorization.

521378750664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4964714 (or 4964707 counting only the distinct ones).

The product of its (nonzero) digits is 8467200, while the sum is 54.

The spelling of 521378750664 in words is "five hundred twenty-one billion, three hundred seventy-eight million, seven hundred fifty thousand, six hundred sixty-four".