18311386 has 4 divisors (see below), whose sum is σ = 27467082. Its totient is φ = 9155692.

The previous prime is 18311353. The next prime is 18311429. The reversal of 18311386 is 68311381.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 68311381 = 281 ⋅243101.

It can be written as a sum of positive squares in only one way, i.e., 18224361 + 87025 = 4269^2 + 295^2 .

It is an unprimeable number.

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, 4577845 + ... + 4577848.

Almost surely, 2^18311386 is an apocalyptic number.

18311386 is a deficient number, since it is larger than the sum of its proper divisors (9155696).

18311386 is an equidigital number, since it uses as much as digits as its factorization.

18311386 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9155695.

The product of its digits is 3456, while the sum is 31.

The square root of 18311386 is about 4279.1805290266. The cubic root of 18311386 is about 263.5767341304.

The spelling of 18311386 in words is "eighteen million, three hundred eleven thousand, three hundred eighty-six".