664920544 has 12 divisors (see below), whose sum is σ = 1309062384. Its totient is φ = 332460256.

The previous prime is 664920533. The next prime is 664920569. The reversal of 664920544 is 445029466.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 664920497 and 664920506.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10389352 + ... + 10389415.

It is an arithmetic number, because the mean of its divisors is an integer number (109088532).

Almost surely, 2^664920544 is an apocalyptic number.

It is an amenable number.

664920544 is a deficient number, since it is larger than the sum of its proper divisors (644141840).

664920544 is a wasteful number, since it uses less digits than its factorization.

664920544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20778777 (or 20778769 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 40.

The square root of 664920544 is about 25786.0532846731. The cubic root of 664920544 is about 872.8171085658.

The spelling of 664920544 in words is "six hundred sixty-four million, nine hundred twenty thousand, five hundred forty-four".