18022591 has 2 divisors, whose sum is σ = 18022592. Its totient is φ = 18022590.

The previous prime is 18022579. The next prime is 18022643. The reversal of 18022591 is 19522081.

It is a weak prime.

It is an emirp because it is prime and its reverse (19522081) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18022591 - 2⁷ = 18022463 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18022391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9011295 + 9011296.

It is an arithmetic number, because the mean of its divisors is an integer number (9011296).

Almost surely, 2^18022591 is an apocalyptic number.

18022591 is a deficient number, since it is larger than the sum of its proper divisors (1).

18022591 is an equidigital number, since it uses as much as digits as its factorization.

18022591 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1440, while the sum is 28.

The square root of 18022591 is about 4245.3022271683. The cubic root of 18022591 is about 262.1837327866.

The spelling of 18022591 in words is "eighteen million, twenty-two thousand, five hundred ninety-one".