18231091 has 2 divisors, whose sum is σ = 18231092. Its totient is φ = 18231090.

The previous prime is 18231079. The next prime is 18231113. The reversal of 18231091 is 19013281.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18231091 - 2²¹ = 16133939 is a prime.

It is not a weakly prime, because it can be changed into another prime (18231071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9115545 + 9115546.

It is an arithmetic number, because the mean of its divisors is an integer number (9115546).

Almost surely, 2^18231091 is an apocalyptic number.

18231091 is a deficient number, since it is larger than the sum of its proper divisors (1).

18231091 is an equidigital number, since it uses as much as digits as its factorization.

18231091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 25.

The square root of 18231091 is about 4269.7881680477. The cubic root of 18231091 is about 263.1909103623.

The spelling of 18231091 in words is "eighteen million, two hundred thirty-one thousand, ninety-one".