664847788020 has 72 divisors (see below), whose sum is σ = 2015787051936. Its totient is φ = 163654837632.

The previous prime is 664847788013. The next prime is 664847788049. The reversal of 664847788020 is 20887748466.

It is a Harshad number since it is a multiple of its sum of digits (60).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 32773282 + ... + 32793561.

It is an arithmetic number, because the mean of its divisors is an integer number (27997042388).

Almost surely, 2^664847788020 is an apocalyptic number.

664847788020 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

664847788020 is an abundant number, since it is smaller than the sum of its proper divisors (1350939263916).

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

664847788020 is a wasteful number, since it uses less digits than its factorization.

664847788020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65566881 (or 65566866 counting only the distinct ones).

The product of its (nonzero) digits is 28901376, while the sum is 60.

The spelling of 664847788020 in words is "six hundred sixty-four billion, eight hundred forty-seven million, seven hundred eighty-eight thousand, twenty".