31897390 has 64 divisors (see below), whose sum is σ = 71539200. Its totient is φ = 9991296.

The previous prime is 31897373. The next prime is 31897399. The reversal of 31897390 is 9379813.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31897399) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 38157 + ... + 38983.

It is an arithmetic number, because the mean of its divisors is an integer number (1117800).

Almost surely, 2^31897390 is an apocalyptic number.

31897390 is an abundant number, since it is smaller than the sum of its proper divisors (39641810).

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

31897390 is a wasteful number, since it uses less digits than its factorization.

31897390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 889.

The product of its (nonzero) digits is 40824, while the sum is 40.

The square root of 31897390 is about 5647.7774389577. Note that the first 3 decimals coincide. The cubic root of 31897390 is about 317.1405069954.

The spelling of 31897390 in words is "thirty-one million, eight hundred ninety-seven thousand, three hundred ninety".