664860877020 has 36 divisors (see below), whose sum is σ = 2016744660840. Its totient is φ = 177296233824.

The previous prime is 664860877007. The next prime is 664860877027. The reversal of 664860877020 is 20778068466.

664860877020 is a `hidden beast` number, since 6 + 6 + 4 + 8 + 608 + 7 + 7 + 0 + 20 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664860877027) 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, 1846835590 + ... + 1846835949.

Almost surely, 2^664860877020 is an apocalyptic number.

664860877020 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

664860877020 is an abundant number, since it is smaller than the sum of its proper divisors (1351883783820).

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

664860877020 is a wasteful number, since it uses less digits than its factorization.

664860877020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3693671554 (or 3693671549 counting only the distinct ones).

The product of its (nonzero) digits is 5419008, while the sum is 54.

The spelling of 664860877020 in words is "six hundred sixty-four billion, eight hundred sixty million, eight hundred seventy-seven thousand, twenty".