664860354638 has 16 divisors (see below), whose sum is σ = 1024419221280. Its totient is φ = 323390349216.

The previous prime is 664860354583. The next prime is 664860354679. The reversal of 664860354638 is 836453068466.

664860354638 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×664860354638² (a number of 24 digits) contains 22 as substring.

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, 329081 + ... + 1199172.

It is an arithmetic number, because the mean of its divisors is an integer number (64026201330).

Almost surely, 2^664860354638 is an apocalyptic number.

664860354638 is a deficient number, since it is larger than the sum of its proper divisors (359558866642).

664860354638 is a wasteful number, since it uses less digits than its factorization.

664860354638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1534171.

The product of its (nonzero) digits is 59719680, while the sum is 59.

The spelling of 664860354638 in words is "six hundred sixty-four billion, eight hundred sixty million, three hundred fifty-four thousand, six hundred thirty-eight".