664657624 has 8 divisors (see below), whose sum is σ = 1246233060. Its totient is φ = 332328808.

The previous prime is 664657559. The next prime is 664657633. The reversal of 664657624 is 426756466.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41541094 + ... + 41541109.

Almost surely, 2^664657624 is an apocalyptic number.

It is an amenable number.

664657624 is a deficient number, since it is larger than the sum of its proper divisors (581575436).

664657624 is a wasteful number, since it uses less digits than its factorization.

664657624 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83082209 (or 83082205 counting only the distinct ones).

The product of its digits is 1451520, while the sum is 46.

The square root of 664657624 is about 25780.9546758843. The cubic root of 664657624 is about 872.7020515465.

It can be divided in two parts, 664657 and 624, that added together give a triangular number (665281 = T₁₁₅₃).

The spelling of 664657624 in words is "six hundred sixty-four million, six hundred fifty-seven thousand, six hundred twenty-four".