640220995 has 8 divisors (see below), whose sum is σ = 770981616. Its totient is φ = 510365856.

The previous prime is 640220989. The next prime is 640221013. The reversal of 640220995 is 599022046.

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

It is a cyclic number.

It is not a de Polignac number, because 640220995 - 2²⁹ = 103350083 is a prime.

It is a Duffinian number.

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, 224812 + ... + 227641.

It is an arithmetic number, because the mean of its divisors is an integer number (96372702).

Almost surely, 2^640220995 is an apocalyptic number.

640220995 is a deficient number, since it is larger than the sum of its proper divisors (130760621).

640220995 is a wasteful number, since it uses less digits than its factorization.

640220995 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 452741.

The product of its (nonzero) digits is 38880, while the sum is 37.

The square root of 640220995 is about 25302.5887015538. The cubic root of 640220995 is about 861.8730561175.

The spelling of 640220995 in words is "six hundred forty million, two hundred twenty thousand, nine hundred ninety-five".