664573637 has 16 divisors (see below), whose sum is σ = 826046592. Its totient is φ = 520603200.

The previous prime is 664573619. The next prime is 664573669. The reversal of 664573637 is 736375466.

It is not a de Polignac number, because 664573637 - 2²⁰ = 663525061 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 664573591 and 664573600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664573607) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26963 + ... + 45344.

It is an arithmetic number, because the mean of its divisors is an integer number (51627912).

Almost surely, 2^664573637 is an apocalyptic number.

It is an amenable number.

664573637 is a deficient number, since it is larger than the sum of its proper divisors (161472955).

664573637 is a wasteful number, since it uses less digits than its factorization.

664573637 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72428.

The product of its digits is 1905120, while the sum is 47.

The square root of 664573637 is about 25779.3257669785. The cubic root of 664573637 is about 872.6652914101.

The spelling of 664573637 in words is "six hundred sixty-four million, five hundred seventy-three thousand, six hundred thirty-seven".