31986091 has 2 divisors, whose sum is σ = 31986092. Its totient is φ = 31986090.

The previous prime is 31986067. The next prime is 31986103. The reversal of 31986091 is 19068913.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 31986091 - 2¹³ = 31977899 is a prime.

It is a super-2 number, since 2×31986091² = 2046220034920562, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 31986091.

It is not a weakly prime, because it can be changed into another prime (31984091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15993045 + 15993046.

It is an arithmetic number, because the mean of its divisors is an integer number (15993046).

Almost surely, 2^31986091 is an apocalyptic number.

31986091 is a deficient number, since it is larger than the sum of its proper divisors (1).

31986091 is an equidigital number, since it uses as much as digits as its factorization.

31986091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11664, while the sum is 37.

The square root of 31986091 is about 5655.6247223450. The cubic root of 31986091 is about 317.4342054750.

The spelling of 31986091 in words is "thirty-one million, nine hundred eighty-six thousand, ninety-one".