31405968 has 100 divisors (see below), whose sum is σ = 99206448. Its totient is φ = 9512640.

The previous prime is 31405961. The next prime is 31405973. The reversal of 31405968 is 86950413.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (31405961) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 13155 + ... + 15357.

Almost surely, 2^31405968 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31405968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49603224).

31405968 is an abundant number, since it is smaller than the sum of its proper divisors (67800480).

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

31405968 is a wasteful number, since it uses less digits than its factorization.

31405968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2234 (or 2219 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The square root of 31405968 is about 5604.1027827833. The cubic root of 31405968 is about 315.5034127366.

The spelling of 31405968 in words is "thirty-one million, four hundred five thousand, nine hundred sixty-eight".