666442403520 has 56 divisors (see below), whose sum is σ = 2115954634224. Its totient is φ = 177717974016.

The previous prime is 666442403453. The next prime is 666442403533. The reversal of 666442403520 is 25304244666.

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, 347104459 + ... + 347106378.

Almost surely, 2^666442403520 is an apocalyptic number.

666442403520 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

666442403520 is an abundant number, since it is smaller than the sum of its proper divisors (1449512230704).

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

666442403520 is a wasteful number, since it uses less digits than its factorization.

666442403520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 694210857 (or 694210847 counting only the distinct ones).

The product of its (nonzero) digits is 829440, while the sum is 42.

The spelling of 666442403520 in words is "six hundred sixty-six billion, four hundred forty-two million, four hundred three thousand, five hundred twenty".