18127997 has 2 divisors, whose sum is σ = 18127998. Its totient is φ = 18127996.

The previous prime is 18127981. The next prime is 18128023. The reversal of 18127997 is 79972181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13060996 + 5067001 = 3614^2 + 2251^2 .

It is a cyclic number.

It is not a de Polignac number, because 18127997 - 2⁴ = 18127981 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18127397) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9063998 + 9063999.

It is an arithmetic number, because the mean of its divisors is an integer number (9063999).

Almost surely, 2^18127997 is an apocalyptic number.

It is an amenable number.

18127997 is a deficient number, since it is larger than the sum of its proper divisors (1).

18127997 is an equidigital number, since it uses as much as digits as its factorization.

18127997 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 63504, while the sum is 44.

The square root of 18127997 is about 4257.6985567323. The cubic root of 18127997 is about 262.6938709903.

The spelling of 18127997 in words is "eighteen million, one hundred twenty-seven thousand, nine hundred ninety-seven".