18311719 has 2 divisors, whose sum is σ = 18311720. Its totient is φ = 18311718.

The previous prime is 18311693. The next prime is 18311723. The reversal of 18311719 is 91711381.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18311719 - 2⁹ = 18311207 is a prime.

It is a super-2 number, since 2×18311719² = 670638105469922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18311759) 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, 9155859 + 9155860.

It is an arithmetic number, because the mean of its divisors is an integer number (9155860).

Almost surely, 2^18311719 is an apocalyptic number.

18311719 is a deficient number, since it is larger than the sum of its proper divisors (1).

18311719 is an equidigital number, since it uses as much as digits as its factorization.

18311719 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1512, while the sum is 31.

The square root of 18311719 is about 4279.2194381686. The cubic root of 18311719 is about 263.5783318708.

The spelling of 18311719 in words is "eighteen million, three hundred eleven thousand, seven hundred nineteen".