640407436 has 12 divisors (see below), whose sum is σ = 1120955920. Its totient is φ = 320134320.

The previous prime is 640407419. The next prime is 640407461. The reversal of 640407436 is 634704046.

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, 7306 + ... + 36526.

Almost surely, 2^640407436 is an apocalyptic number.

It is an amenable number.

640407436 is a deficient number, since it is larger than the sum of its proper divisors (480548484).

640407436 is a wasteful number, since it uses less digits than its factorization.

640407436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34704 (or 34702 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 34.

The square root of 640407436 is about 25306.2726611408. The cubic root of 640407436 is about 861.9567110221.

The spelling of 640407436 in words is "six hundred forty million, four hundred seven thousand, four hundred thirty-six".