18638897 has 2 divisors, whose sum is σ = 18638898. Its totient is φ = 18638896.

The previous prime is 18638863. The next prime is 18638899. The reversal of 18638897 is 79883681.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17272336 + 1366561 = 4156^2 + 1169^2 .

It is a cyclic number.

It is not a de Polignac number, because 18638897 - 2⁶ = 18638833 is a prime.

Together with 18638899, 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 (18638899) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9319448 + 9319449.

It is an arithmetic number, because the mean of its divisors is an integer number (9319449).

Almost surely, 2^18638897 is an apocalyptic number.

It is an amenable number.

18638897 is a deficient number, since it is larger than the sum of its proper divisors (1).

18638897 is an equidigital number, since it uses as much as digits as its factorization.

18638897 is an evil number, because the sum of its binary digits is even.

The product of its digits is 580608, while the sum is 50.

The square root of 18638897 is about 4317.2788883740. The cubic root of 18638897 is about 265.1388710839.

The spelling of 18638897 in words is "eighteen million, six hundred thirty-eight thousand, eight hundred ninety-seven".