640810474 has 8 divisors (see below), whose sum is σ = 987194628. Its totient is φ = 311745600.

The previous prime is 640810459. The next prime is 640810487. The reversal of 640810474 is 474018046.

It can be written as a sum of positive squares in 2 ways, for example, as 570971025 + 69839449 = 23895^2 + 8357^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4329727 + ... + 4329874.

Almost surely, 2^640810474 is an apocalyptic number.

640810474 is a deficient number, since it is larger than the sum of its proper divisors (346384154).

640810474 is a wasteful number, since it uses less digits than its factorization.

640810474 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8659640.

The product of its (nonzero) digits is 21504, while the sum is 34.

The square root of 640810474 is about 25314.2346121703. The cubic root of 640810474 is about 862.1374961683.

The spelling of 640810474 in words is "six hundred forty million, eight hundred ten thousand, four hundred seventy-four".