399444664 has 16 divisors (see below), whose sum is σ = 749586600. Its totient is φ = 199554912.

The previous prime is 399444659. The next prime is 399444667. The reversal of 399444664 is 466444993.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399444667) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10482 + ... + 30145.

Almost surely, 2^399444664 is an apocalyptic number.

It is an amenable number.

399444664 is a deficient number, since it is larger than the sum of its proper divisors (350141936).

399444664 is a wasteful number, since it uses less digits than its factorization.

399444664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41862 (or 41858 counting only the distinct ones).

The product of its digits is 2239488, while the sum is 49.

The square root of 399444664 is about 19986.1117779322. Note that the first 3 decimals coincide. The cubic root of 399444664 is about 736.4651625885.

The spelling of 399444664 in words is "three hundred ninety-nine million, four hundred forty-four thousand, six hundred sixty-four".