31938561 has 12 divisors (see below), whose sum is σ = 46210788. Its totient is φ = 21256704.

The previous prime is 31938547. The next prime is 31938589. The reversal of 31938561 is 16583913.

It is a happy number.

31938561 is a `hidden beast` number, since 3 + 1 + 93 + 8 + 561 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 13068225 + 18870336 = 3615^2 + 4344^2 .

It is not a de Polignac number, because 31938561 - 2⁶ = 31938497 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31938061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3421 + ... + 8693.

It is an arithmetic number, because the mean of its divisors is an integer number (3850899).

Almost surely, 2^31938561 is an apocalyptic number.

It is an amenable number.

31938561 is a deficient number, since it is larger than the sum of its proper divisors (14272227).

31938561 is a wasteful number, since it uses less digits than its factorization.

31938561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5952 (or 5949 counting only the distinct ones).

The product of its digits is 19440, while the sum is 36.

The square root of 31938561 is about 5651.4211487023. The cubic root of 31938561 is about 317.2768961915.

The spelling of 31938561 in words is "thirty-one million, nine hundred thirty-eight thousand, five hundred sixty-one".