640930131 has 32 divisors (see below), whose sum is σ = 984571200. Its totient is φ = 411586560.

The previous prime is 640930127. The next prime is 640930133. The reversal of 640930131 is 131039046.

640930131 is a `hidden beast` number, since 640 + 9 + 3 + 0 + 13 + 1 = 666.

640930131 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 640930131 - 2² = 640930127 is a prime.

It is a super-2 number, since 2×640930131² = 821582865647354322, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 640930095 and 640930104.

It is not an unprimeable number, because it can be changed into a prime (640930133) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 501265 + ... + 502541.

It is an arithmetic number, because the mean of its divisors is an integer number (30767850).

Almost surely, 2^640930131 is an apocalyptic number.

640930131 is a deficient number, since it is larger than the sum of its proper divisors (343641069).

640930131 is a wasteful number, since it uses less digits than its factorization.

640930131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1956 (or 1950 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 27.

The square root of 640930131 is about 25316.5979349517. The cubic root of 640930131 is about 862.1911544496.

Adding to 640930131 its reverse (131039046), we get a palindrome (771969177).

The spelling of 640930131 in words is "six hundred forty million, nine hundred thirty thousand, one hundred thirty-one".