31690400 has 72 divisors (see below), whose sum is σ = 88431840. Its totient is φ = 10863360.

The previous prime is 31690391. The next prime is 31690403. The reversal of 31690400 is 409613.

It is not an unprimeable number, because it can be changed into a prime (31690403) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2771 + ... + 8429.

It is an arithmetic number, because the mean of its divisors is an integer number (1228220).

Almost surely, 2^31690400 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 31690400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44215920).

31690400 is an abundant number, since it is smaller than the sum of its proper divisors (56741440).

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

31690400 is a wasteful number, since it uses less digits than its factorization.

31690400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5686 (or 5673 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 23.

The square root of 31690400 is about 5629.4227057488. The cubic root of 31690400 is about 316.4530168590.

The spelling of 31690400 in words is "thirty-one million, six hundred ninety thousand, four hundred".