18311329 has 6 divisors (see below), whose sum is σ = 19452134. Its totient is φ = 17233920.

The previous prime is 18311327. The next prime is 18311353. The reversal of 18311329 is 92311381.

It can be written as a sum of positive squares in 3 ways, for example, as 7102225 + 11209104 = 2665^2 + 3348^2 .

It is not a de Polignac number, because 18311329 - 2¹ = 18311327 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18311297 and 18311306.

It is not an unprimeable number, because it can be changed into a prime (18311323) 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 in 5 ways as a sum of consecutive naturals, for example, 31392 + ... + 31969.

Almost surely, 2^18311329 is an apocalyptic number.

It is an amenable number.

18311329 is a deficient number, since it is larger than the sum of its proper divisors (1140805).

18311329 is an equidigital number, since it uses as much as digits as its factorization.

18311329 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63395 (or 63378 counting only the distinct ones).

The product of its digits is 1296, while the sum is 28.

The square root of 18311329 is about 4279.1738688677. The cubic root of 18311329 is about 263.5764606414.

It can be divided in two parts, 1831 and 1329, that added together give a triangular number (3160 = T₇₉).

The spelling of 18311329 in words is "eighteen million, three hundred eleven thousand, three hundred twenty-nine".