18997087 has 2 divisors, whose sum is σ = 18997088. Its totient is φ = 18997086.

The previous prime is 18997073. The next prime is 18997129. The reversal of 18997087 is 78079981.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18997087 - 2⁷ = 18996959 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18997087.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18997387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9498543 + 9498544.

It is an arithmetic number, because the mean of its divisors is an integer number (9498544).

Almost surely, 2^18997087 is an apocalyptic number.

18997087 is a deficient number, since it is larger than the sum of its proper divisors (1).

18997087 is an equidigital number, since it uses as much as digits as its factorization.

18997087 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 254016, while the sum is 49.

The square root of 18997087 is about 4358.5647867159. The cubic root of 18997087 is about 266.8265272384.

The spelling of 18997087 in words is "eighteen million, nine hundred ninety-seven thousand, eighty-seven".