18311693 has 2 divisors, whose sum is σ = 18311694. Its totient is φ = 18311692.

The previous prime is 18311641. The next prime is 18311719. The reversal of 18311693 is 39611381.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14915044 + 3396649 = 3862^2 + 1843^2 .

It is a cyclic number.

It is not a de Polignac number, because 18311693 - 2²⁰ = 17263117 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18311893) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9155846 + 9155847.

It is an arithmetic number, because the mean of its divisors is an integer number (9155847).

Almost surely, 2^18311693 is an apocalyptic number.

It is an amenable number.

18311693 is a deficient number, since it is larger than the sum of its proper divisors (1).

18311693 is an equidigital number, since it uses as much as digits as its factorization.

18311693 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3888, while the sum is 32.

The square root of 18311693 is about 4279.2164002303. The cubic root of 18311693 is about 263.5782071230.

The spelling of 18311693 in words is "eighteen million, three hundred eleven thousand, six hundred ninety-three".