664312540 has 24 divisors (see below), whose sum is σ = 1401321600. Its totient is φ = 264531648.

The previous prime is 664312513. The next prime is 664312543. The reversal of 664312540 is 45213466.

It is a super-2 number, since 2×664312540² = 882622301602503200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664312543) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 70015 + ... + 78934.

It is an arithmetic number, because the mean of its divisors is an integer number (58388400).

Almost surely, 2^664312540 is an apocalyptic number.

It is an amenable number.

664312540 is an abundant number, since it is smaller than the sum of its proper divisors (737009060).

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

664312540 is a wasteful number, since it uses less digits than its factorization.

664312540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149181 (or 149179 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 31.

The square root of 664312540 is about 25774.2611921273. The cubic root of 664312540 is about 872.5509924960.

The spelling of 664312540 in words is "six hundred sixty-four million, three hundred twelve thousand, five hundred forty".