6640125631 has 4 divisors (see below), whose sum is σ = 6854323264. Its totient is φ = 6425928000.

The previous prime is 6640125619. The next prime is 6640125649. The reversal of 6640125631 is 1365210466.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 6640125631 - 2²⁵ = 6606571199 is a prime.

It is a super-2 number, since 2×6640125631² = 88182536790926296322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6640125731) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 107098770 + ... + 107098831.

It is an arithmetic number, because the mean of its divisors is an integer number (1713580816).

Almost surely, 2^6640125631 is an apocalyptic number.

6640125631 is a deficient number, since it is larger than the sum of its proper divisors (214197633).

6640125631 is a wasteful number, since it uses less digits than its factorization.

6640125631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214197632.

The product of its (nonzero) digits is 25920, while the sum is 34.

The square root of 6640125631 is about 81486.9660191125. The cubic root of 6640125631 is about 1879.5711288772.

The spelling of 6640125631 in words is "six billion, six hundred forty million, one hundred twenty-five thousand, six hundred thirty-one".