61640631 has 48 divisors (see below), whose sum is σ = 102080160. Its totient is φ = 35562240.

The previous prime is 61640597. The next prime is 61640633. The reversal of 61640631 is 13604616.

61640631 is a `hidden beast` number, since 616 + 40 + 6 + 3 + 1 = 666.

It is not a de Polignac number, because 61640631 - 2⁹ = 61640119 is a prime.

It is a super-2 number, since 2×61640631² = 7599134780156322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 61640595 and 61640604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61640633) by changing a digit.

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 47 ways as a sum of consecutive naturals, for example, 125296 + ... + 125786.

It is an arithmetic number, because the mean of its divisors is an integer number (2126670).

Almost surely, 2^61640631 is an apocalyptic number.

61640631 is a deficient number, since it is larger than the sum of its proper divisors (40439529).

61640631 is a wasteful number, since it uses less digits than its factorization.

61640631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 576 (or 573 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The square root of 61640631 is about 7851.1547558305. The cubic root of 61640631 is about 395.0229778867.

The spelling of 61640631 in words is "sixty-one million, six hundred forty thousand, six hundred thirty-one".