18797021 has 2 divisors, whose sum is σ = 18797022. Its totient is φ = 18797020.

The previous prime is 18796993. The next prime is 18797027. The reversal of 18797021 is 12079781.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13060996 + 5736025 = 3614^2 + 2395^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18797021 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18797027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9398510 + 9398511.

It is an arithmetic number, because the mean of its divisors is an integer number (9398511).

Almost surely, 2^18797021 is an apocalyptic number.

It is an amenable number.

18797021 is a deficient number, since it is larger than the sum of its proper divisors (1).

18797021 is an equidigital number, since it uses as much as digits as its factorization.

18797021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7056, while the sum is 35.

The square root of 18797021 is about 4335.5531365675. The cubic root of 18797021 is about 265.8865336627.

The spelling of 18797021 in words is "eighteen million, seven hundred ninety-seven thousand, twenty-one".