18992681 has 2 divisors, whose sum is σ = 18992682. Its totient is φ = 18992680.

The previous prime is 18992669. The next prime is 18992683. The reversal of 18992681 is 18629981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18490000 + 502681 = 4300^2 + 709^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18992681 is a prime.

It is a super-2 number, since 2×18992681² = 721443863135522, which contains 22 as substring.

Together with 18992683, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18992683) 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, 9496340 + 9496341.

It is an arithmetic number, because the mean of its divisors is an integer number (9496341).

Almost surely, 2^18992681 is an apocalyptic number.

It is an amenable number.

18992681 is a deficient number, since it is larger than the sum of its proper divisors (1).

18992681 is an equidigital number, since it uses as much as digits as its factorization.

18992681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 62208, while the sum is 44.

The square root of 18992681 is about 4358.0593157964. The cubic root of 18992681 is about 266.8058972583.

The spelling of 18992681 in words is "eighteen million, nine hundred ninety-two thousand, six hundred eighty-one".