666440624 has 10 divisors (see below), whose sum is σ = 1291228740. Its totient is φ = 333220304.

The previous prime is 666440597. The next prime is 666440627. The reversal of 666440624 is 426044666.

666440624 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (666440627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20826254 + ... + 20826285.

It is an arithmetic number, because the mean of its divisors is an integer number (129122874).

Almost surely, 2^666440624 is an apocalyptic number.

It is an amenable number.

666440624 is a deficient number, since it is larger than the sum of its proper divisors (624788116).

666440624 is a wasteful number, since it uses less digits than its factorization.

666440624 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41652547 (or 41652541 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 38.

The square root of 666440624 is about 25815.5113061895. The cubic root of 666440624 is about 873.4817203463.

The spelling of 666440624 in words is "six hundred sixty-six million, four hundred forty thousand, six hundred twenty-four".