31120091 has 2 divisors, whose sum is σ = 31120092. Its totient is φ = 31120090.

The previous prime is 31120079. The next prime is 31120109. The reversal of 31120091 is 19002113.

It is a happy number.

Together with next prime (31120109) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 31120091 - 2⁶ = 31120027 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (31120031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15560045 + 15560046.

It is an arithmetic number, because the mean of its divisors is an integer number (15560046).

Almost surely, 2^31120091 is an apocalyptic number.

31120091 is a deficient number, since it is larger than the sum of its proper divisors (1).

31120091 is an equidigital number, since it uses as much as digits as its factorization.

31120091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 54, while the sum is 17.

The square root of 31120091 is about 5578.5384286567. The cubic root of 31120091 is about 314.5431893728.

It can be divided in two parts, 311 and 20091, that added together give a palindrome (20402).

The spelling of 31120091 in words is "thirty-one million, one hundred twenty thousand, ninety-one".