640137895 has 8 divisors (see below), whose sum is σ = 768872304. Its totient is φ = 511639104.

The previous prime is 640137889. The next prime is 640137931. The reversal of 640137895 is 598731046.

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 640137895 - 2⁷ = 640137767 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 52869 + ... + 63838.

It is an arithmetic number, because the mean of its divisors is an integer number (96109038).

Almost surely, 2^640137895 is an apocalyptic number.

640137895 is a deficient number, since it is larger than the sum of its proper divisors (128734409).

640137895 is a wasteful number, since it uses less digits than its factorization.

640137895 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117809.

The product of its (nonzero) digits is 181440, while the sum is 43.

The square root of 640137895 is about 25300.9465237963. The cubic root of 640137895 is about 861.8357644372.

The spelling of 640137895 in words is "six hundred forty million, one hundred thirty-seven thousand, eight hundred ninety-five".