31940040 has 64 divisors (see below), whose sum is σ = 104535360. Its totient is φ = 7742720.

The previous prime is 31940033. The next prime is 31940047. The reversal of 31940040 is 4004913.

It is an interprime number because it is at equal distance from previous prime (31940033) and next prime (31940047).

It is a junction number, because it is equal to n+sod(n) for n = 31939989 and 31940016.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31940047) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10779 + ... + 13418.

It is an arithmetic number, because the mean of its divisors is an integer number (1633365).

Almost surely, 2^31940040 is an apocalyptic number.

31940040 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

31940040 is an abundant number, since it is smaller than the sum of its proper divisors (72595320).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31940040 is a wasteful number, since it uses less digits than its factorization.

31940040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24222 (or 24218 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 31940040 is about 5651.5519992299. The cubic root of 31940040 is about 317.2817935661.

Adding to 31940040 its reverse (4004913), we get a palindrome (35944953).

The spelling of 31940040 in words is "thirty-one million, nine hundred forty thousand, forty".