664472538 has 32 divisors (see below), whose sum is σ = 1524241920. Its totient is φ = 214345440.

The previous prime is 664472537. The next prime is 664472587. The reversal of 664472538 is 835274466.

664472538 is a `hidden beast` number, since 6 + 6 + 44 + 72 + 538 = 666.

It is a super-2 number, since 2×664472538² = 883047507512322888, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 664472493 and 664472502.

It is not an unprimeable number, because it can be changed into a prime (664472531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 196795 + ... + 200142.

It is an arithmetic number, because the mean of its divisors is an integer number (47632560).

Almost surely, 2^664472538 is an apocalyptic number.

664472538 is an abundant number, since it is smaller than the sum of its proper divisors (859769382).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

664472538 is a wasteful number, since it uses less digits than its factorization.

664472538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 396979 (or 396973 counting only the distinct ones).

The product of its digits is 967680, while the sum is 45.

The square root of 664472538 is about 25777.3648381676. The cubic root of 664472538 is about 872.6210374416.

The spelling of 664472538 in words is "six hundred sixty-four million, four hundred seventy-two thousand, five hundred thirty-eight".