31990369 has 4 divisors (see below), whose sum is σ = 32063680. Its totient is φ = 31917060.

The previous prime is 31990367. The next prime is 31990381. The reversal of 31990369 is 96309913.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 31990369 - 2¹ = 31990367 is a prime.

It is a super-2 number, since 2×31990369² = 2046767417512322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31990363) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35997 + ... + 36874.

It is an arithmetic number, because the mean of its divisors is an integer number (8015920).

Almost surely, 2^31990369 is an apocalyptic number.

It is an amenable number.

31990369 is a deficient number, since it is larger than the sum of its proper divisors (73311).

31990369 is an equidigital number, since it uses as much as digits as its factorization.

31990369 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73310.

The product of its (nonzero) digits is 39366, while the sum is 40.

The square root of 31990369 is about 5656.0029172553. The cubic root of 31990369 is about 317.4483566571.

The spelling of 31990369 in words is "thirty-one million, nine hundred ninety thousand, three hundred sixty-nine".