31319990 has 32 divisors (see below), whose sum is σ = 61417440. Its totient is φ = 11430144.

The previous prime is 31319987. The next prime is 31320007. The reversal of 31319990 is 9991313.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 31319990.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10217 + ... + 12923.

It is an arithmetic number, because the mean of its divisors is an integer number (1919295).

Almost surely, 2^31319990 is an apocalyptic number.

31319990 is a deficient number, since it is larger than the sum of its proper divisors (30097450).

31319990 is a wasteful number, since it uses less digits than its factorization.

31319990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2816.

The product of its (nonzero) digits is 6561, while the sum is 35.

The square root of 31319990 is about 5596.4265384261. The cubic root of 31319990 is about 315.2152388018.

The spelling of 31319990 in words is "thirty-one million, three hundred nineteen thousand, nine hundred ninety".