31991069 has 12 divisors (see below), whose sum is σ = 35303520. Its totient is φ = 28967400.

The previous prime is 31991053. The next prime is 31991087. The reversal of 31991069 is 96019913.

31991069 = 453² + 454² + ... + 573².

It is not a de Polignac number, because 31991069 - 2⁴ = 31991053 is a prime.

It is a super-2 number, since 2×31991069² = 2046856991525522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31994069) 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, 50384 + ... + 51014.

It is an arithmetic number, because the mean of its divisors is an integer number (2941960).

Almost surely, 2^31991069 is an apocalyptic number.

It is an amenable number.

31991069 is a deficient number, since it is larger than the sum of its proper divisors (3312451).

31991069 is a wasteful number, since it uses less digits than its factorization.

31991069 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1072 (or 1061 counting only the distinct ones).

The product of its (nonzero) digits is 13122, while the sum is 38.

The square root of 31991069 is about 5656.0647980729. The cubic root of 31991069 is about 317.4506720647.

The spelling of 31991069 in words is "thirty-one million, nine hundred ninety-one thousand, sixty-nine".