664399195020 has 72 divisors (see below), whose sum is σ = 2198557342800. Its totient is φ = 161066471040.

The previous prime is 664399194973. The next prime is 664399195039. The reversal of 664399195020 is 20591993466.

664399195020 is a `hidden beast` number, since 6 + 6 + 43 + 9 + 91 + 9 + 502 + 0 = 666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 167775595 + ... + 167779554.

It is an arithmetic number, because the mean of its divisors is an integer number (30535518650).

Almost surely, 2^664399195020 is an apocalyptic number.

664399195020 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

664399195020 is an abundant number, since it is smaller than the sum of its proper divisors (1534158147780).

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

664399195020 is a wasteful number, since it uses less digits than its factorization.

664399195020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 335555175 (or 335555170 counting only the distinct ones).

The product of its (nonzero) digits is 3149280, while the sum is 54.

The spelling of 664399195020 in words is "six hundred sixty-four billion, three hundred ninety-nine million, one hundred ninety-five thousand, twenty".