666031920 has 80 divisors (see below), whose sum is σ = 2103695712. Its totient is φ = 174254080.

The previous prime is 666031853. The next prime is 666031963. The reversal of 666031920 is 29130666.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13461 + ... + 38900.

Almost surely, 2^666031920 is an apocalyptic number.

666031920 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

666031920 is an abundant number, since it is smaller than the sum of its proper divisors (1437663792).

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

666031920 is a wasteful number, since it uses less digits than its factorization.

666031920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52430 (or 52424 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 33.

The square root of 666031920 is about 25807.5942311561. The cubic root of 666031920 is about 873.3031255536.

The spelling of 666031920 in words is "six hundred sixty-six million, thirty-one thousand, nine hundred twenty".