666400044 has 48 divisors (see below), whose sum is σ = 1624089600. Its totient is φ = 212458176.

The previous prime is 666400037. The next prime is 666400057. The reversal of 666400044 is 440004666.

It is a junction number, because it is equal to n+sod(n) for n = 666399984 and 666400020.

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, 13477 + ... + 38915.

It is an arithmetic number, because the mean of its divisors is an integer number (33835200).

Almost surely, 2^666400044 is an apocalyptic number.

It is an amenable number.

666400044 is an abundant number, since it is smaller than the sum of its proper divisors (957689556).

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

666400044 is a wasteful number, since it uses less digits than its factorization.

666400044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25542 (or 25540 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 30.

The square root of 666400044 is about 25814.7253326469. The cubic root of 666400044 is about 873.4639910311.

The spelling of 666400044 in words is "six hundred sixty-six million, four hundred thousand, forty-four".