18492581 has 2 divisors, whose sum is σ = 18492582. Its totient is φ = 18492580.

The previous prime is 18492571. The next prime is 18492619. The reversal of 18492581 is 18529481.

It is an a-pointer prime, because the next prime (18492619) can be obtained adding 18492581 to its sum of digits (38).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14371681 + 4120900 = 3791^2 + 2030^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18492581 is a prime.

It is a super-2 number, since 2×18492581² = 683951104083122, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18492521) 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, 9246290 + 9246291.

It is an arithmetic number, because the mean of its divisors is an integer number (9246291).

Almost surely, 2^18492581 is an apocalyptic number.

It is an amenable number.

18492581 is a deficient number, since it is larger than the sum of its proper divisors (1).

18492581 is an equidigital number, since it uses as much as digits as its factorization.

18492581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 23040, while the sum is 38.

The square root of 18492581 is about 4300.3001058066. The cubic root of 18492581 is about 264.4432645489.

The spelling of 18492581 in words is "eighteen million, four hundred ninety-two thousand, five hundred eighty-one".