640295646 has 32 divisors (see below), whose sum is σ = 1293508608. Its totient is φ = 211286880.

The previous prime is 640295639. The next prime is 640295657. The reversal of 640295646 is 646592046.

It is a junction number, because it is equal to n+sod(n) for n = 640295598 and 640295607.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 626616 + ... + 627636.

It is an arithmetic number, because the mean of its divisors is an integer number (40422144).

Almost surely, 2^640295646 is an apocalyptic number.

640295646 is an abundant number, since it is smaller than the sum of its proper divisors (653212962).

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

640295646 is a wasteful number, since it uses less digits than its factorization.

640295646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1976.

The product of its (nonzero) digits is 311040, while the sum is 42.

The square root of 640295646 is about 25304.0638238209. The cubic root of 640295646 is about 861.9065535012.

The spelling of 640295646 in words is "six hundred forty million, two hundred ninety-five thousand, six hundred forty-six".