640442524 has 12 divisors (see below), whose sum is σ = 1124427304. Its totient is φ = 319177584.

The previous prime is 640442503. The next prime is 640442527. The reversal of 640442524 is 425244046.

It is a happy number.

It is a hoax number, since the sum of its digits (31) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640442527) 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, 259539 + ... + 261994.

Almost surely, 2^640442524 is an apocalyptic number.

It is an amenable number.

640442524 is a deficient number, since it is larger than the sum of its proper divisors (483984780).

640442524 is a wasteful number, since it uses less digits than its factorization.

640442524 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 521844 (or 521842 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 31.

The square root of 640442524 is about 25306.9659184976. The cubic root of 640442524 is about 861.9724529717.

The spelling of 640442524 in words is "six hundred forty million, four hundred forty-two thousand, five hundred twenty-four".