640199915 has 16 divisors (see below), whose sum is σ = 774360000. Its totient is φ = 508096512.

The previous prime is 640199909. The next prime is 640199921. The reversal of 640199915 is 519991046.

640199915 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (640199909) and next prime (640199921).

It is a cyclic number.

It is not a de Polignac number, because 640199915 - 2¹² = 640195819 is a prime.

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, 446039 + ... + 447471.

It is an arithmetic number, because the mean of its divisors is an integer number (48397500).

Almost surely, 2^640199915 is an apocalyptic number.

640199915 is a deficient number, since it is larger than the sum of its proper divisors (134160085).

640199915 is a wasteful number, since it uses less digits than its factorization.

640199915 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2086.

The product of its (nonzero) digits is 87480, while the sum is 44.

The square root of 640199915 is about 25302.1721399567. The cubic root of 640199915 is about 861.8635966321.

The spelling of 640199915 in words is "six hundred forty million, one hundred ninety-nine thousand, nine hundred fifteen".