18534491 has 2 divisors, whose sum is σ = 18534492. Its totient is φ = 18534490.

The previous prime is 18534487. The next prime is 18534499. The reversal of 18534491 is 19443581.

It is a weak prime.

It is an emirp because it is prime and its reverse (19443581) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18534491 - 2² = 18534487 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18534499) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9267245 + 9267246.

It is an arithmetic number, because the mean of its divisors is an integer number (9267246).

Almost surely, 2^18534491 is an apocalyptic number.

18534491 is a deficient number, since it is larger than the sum of its proper divisors (1).

18534491 is an equidigital number, since it uses as much as digits as its factorization.

18534491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17280, while the sum is 35.

The square root of 18534491 is about 4305.1702637643. The cubic root of 18534491 is about 264.6428843381.

The spelling of 18534491 in words is "eighteen million, five hundred thirty-four thousand, four hundred ninety-one".