640002456 has 48 divisors (see below), whose sum is σ = 1775624760. Its totient is φ = 208129920.

The previous prime is 640002443. The next prime is 640002481. The reversal of 640002456 is 654200046.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 105450 + ... + 111353.

Almost surely, 2^640002456 is an apocalyptic number.

It is an amenable number.

640002456 is an abundant number, since it is smaller than the sum of its proper divisors (1135622304).

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

640002456 is a wasteful number, since it uses less digits than its factorization.

640002456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 216856 (or 216849 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 27.

The square root of 640002456 is about 25298.2698222625. The cubic root of 640002456 is about 861.7749783638.

The spelling of 640002456 in words is "six hundred forty million, two thousand, four hundred fifty-six".