640461456 has 30 divisors (see below), whose sum is σ = 1792402950. Its totient is φ = 213487104.

The previous prime is 640461439. The next prime is 640461541. The reversal of 640461456 is 654164046.

640461456 is a `hidden beast` number, since 640 + 4 + 6 + 1 + 4 + 5 + 6 = 666.

It can be written as a sum of positive squares in only one way, i.e., 543635856 + 96825600 = 23316^2 + 9840^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 640461456.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2223681 + ... + 2223968.

It is an arithmetic number, because the mean of its divisors is an integer number (59746765).

Almost surely, 2^640461456 is an apocalyptic number.

It is an amenable number.

640461456 is an abundant number, since it is smaller than the sum of its proper divisors (1151941494).

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

640461456 is a wasteful number, since it uses less digits than its factorization.

640461456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4447663 (or 4447654 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 36.

The square root of 640461456 is about 25307.3399629436. The cubic root of 640461456 is about 861.9809464227.

The spelling of 640461456 in words is "six hundred forty million, four hundred sixty-one thousand, four hundred fifty-six".