18397237 has 2 divisors, whose sum is σ = 18397238. Its totient is φ = 18397236.

The previous prime is 18397231. The next prime is 18397261. The reversal of 18397237 is 73279381.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11771761 + 6625476 = 3431^2 + 2574^2 .

It is a cyclic number.

It is not a de Polignac number, because 18397237 - 2⁷ = 18397109 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18397237.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18397231) 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, 9198618 + 9198619.

It is an arithmetic number, because the mean of its divisors is an integer number (9198619).

Almost surely, 2^18397237 is an apocalyptic number.

It is an amenable number.

18397237 is a deficient number, since it is larger than the sum of its proper divisors (1).

18397237 is an equidigital number, since it uses as much as digits as its factorization.

18397237 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 63504, while the sum is 40.

The square root of 18397237 is about 4289.2000419659. The cubic root of 18397237 is about 263.9880092886.

The spelling of 18397237 in words is "eighteen million, three hundred ninety-seven thousand, two hundred thirty-seven".