666542444 has 6 divisors (see below), whose sum is σ = 1166449284. Its totient is φ = 333271220.

The previous prime is 666542423. The next prime is 666542497. The reversal of 666542444 is 444245666.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83317802 + ... + 83317809.

It is an arithmetic number, because the mean of its divisors is an integer number (194408214).

Almost surely, 2^666542444 is an apocalyptic number.

It is an amenable number.

666542444 is a deficient number, since it is larger than the sum of its proper divisors (499906840).

666542444 is a wasteful number, since it uses less digits than its factorization.

666542444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166635615 (or 166635613 counting only the distinct ones).

The product of its digits is 552960, while the sum is 41.

The square root of 666542444 is about 25817.4833010501. The cubic root of 666542444 is about 873.5262021184.

The spelling of 666542444 in words is "six hundred sixty-six million, five hundred forty-two thousand, four hundred forty-four".