640217524 has 12 divisors (see below), whose sum is σ = 1120581504. Its totient is φ = 320051384.

The previous prime is 640217491. The next prime is 640217527. The reversal of 640217524 is 425712046.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640217527) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19779 + ... + 40885.

It is an arithmetic number, because the mean of its divisors is an integer number (93381792).

Almost surely, 2^640217524 is an apocalyptic number.

It is an amenable number.

640217524 is a deficient number, since it is larger than the sum of its proper divisors (480363980).

640217524 is a wasteful number, since it uses less digits than its factorization.

640217524 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28694 (or 28692 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 31.

The square root of 640217524 is about 25302.5201116411. The cubic root of 640217524 is about 861.8714985476.

The spelling of 640217524 in words is "six hundred forty million, two hundred seventeen thousand, five hundred twenty-four".