664399544 has 16 divisors (see below), whose sum is σ = 1249450800. Its totient is φ = 331212672.

The previous prime is 664399517. The next prime is 664399553. The reversal of 664399544 is 445993466.

It is a junction number, because it is equal to n+sod(n) for n = 664399492 and 664399501.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 120524 + ... + 125915.

It is an arithmetic number, because the mean of its divisors is an integer number (78090675).

Almost surely, 2^664399544 is an apocalyptic number.

It is an amenable number.

664399544 is a deficient number, since it is larger than the sum of its proper divisors (585051256).

664399544 is a wasteful number, since it uses less digits than its factorization.

664399544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 246782 (or 246778 counting only the distinct ones).

The product of its digits is 2799360, while the sum is 50.

The square root of 664399544 is about 25775.9489447042. The cubic root of 664399544 is about 872.5890830573.

The spelling of 664399544 in words is "six hundred sixty-four million, three hundred ninety-nine thousand, five hundred forty-four".