640640346 has 16 divisors (see below), whose sum is σ = 1281723744. Its totient is φ = 213472944.

The previous prime is 640640339. The next prime is 640640353. The reversal of 640640346 is 643046046.

It is an interprime number because it is at equal distance from previous prime (640640339) and next prime (640640353).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2100 + ... + 35856.

It is an arithmetic number, because the mean of its divisors is an integer number (80107734).

Almost surely, 2^640640346 is an apocalyptic number.

640640346 is an abundant number, since it is smaller than the sum of its proper divisors (641083398).

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

640640346 is a wasteful number, since it uses less digits than its factorization.

640640346 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36925.

The product of its (nonzero) digits is 41472, while the sum is 33.

The square root of 640640346 is about 25310.8740662981. The cubic root of 640640346 is about 862.0611934673.

The spelling of 640640346 in words is "six hundred forty million, six hundred forty thousand, three hundred forty-six".