231136091 has 2 divisors, whose sum is σ = 231136092. Its totient is φ = 231136090.

The previous prime is 231136049. The next prime is 231136109. The reversal of 231136091 is 190631132.

Together with next prime (231136109) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-231136091 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 231136091.

It is not a weakly prime, because it can be changed into another prime (231130091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115568045 + 115568046.

It is an arithmetic number, because the mean of its divisors is an integer number (115568046).

Almost surely, 2^231136091 is an apocalyptic number.

231136091 is a deficient number, since it is larger than the sum of its proper divisors (1).

231136091 is an equidigital number, since it uses as much as digits as its factorization.

231136091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 972, while the sum is 26.

The square root of 231136091 is about 15203.1605595679. The cubic root of 231136091 is about 613.6997147022.

The spelling of 231136091 in words is "two hundred thirty-one million, one hundred thirty-six thousand, ninety-one".