666621344 has 24 divisors (see below), whose sum is σ = 1319018400. Its totient is φ = 331632576.

The previous prime is 666621331. The next prime is 666621367. The reversal of 666621344 is 443126666.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 666621298 and 666621307.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45974 + ... + 58709.

It is an arithmetic number, because the mean of its divisors is an integer number (54959100).

Almost surely, 2^666621344 is an apocalyptic number.

It is an amenable number.

666621344 is a deficient number, since it is larger than the sum of its proper divisors (652397056).

666621344 is a wasteful number, since it uses less digits than its factorization.

666621344 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104892 (or 104884 counting only the distinct ones).

The product of its digits is 124416, while the sum is 38.

The square root of 666621344 is about 25819.0112901327. The cubic root of 666621344 is about 873.5606677896.

The spelling of 666621344 in words is "six hundred sixty-six million, six hundred twenty-one thousand, three hundred forty-four".