640302406 has 8 divisors (see below), whose sum is σ = 969265440. Its totient is φ = 317213928.

The previous prime is 640302391. The next prime is 640302431. The reversal of 640302406 is 604203046.

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

It is a super-2 number, since 2×640302406² = 819974342258777672, which contains 22 as substring.

It is a congruent number.

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, 1468366 + ... + 1468801.

It is an arithmetic number, because the mean of its divisors is an integer number (121158180).

Almost surely, 2^640302406 is an apocalyptic number.

640302406 is a deficient number, since it is larger than the sum of its proper divisors (328963034).

640302406 is a wasteful number, since it uses less digits than its factorization.

640302406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2937278.

The product of its (nonzero) digits is 3456, while the sum is 25.

The square root of 640302406 is about 25304.1973988506. The cubic root of 640302406 is about 861.9095867187.

The spelling of 640302406 in words is "six hundred forty million, three hundred two thousand, four hundred six".