18186139 has 4 divisors (see below), whose sum is σ = 18233280. Its totient is φ = 18139000.

The previous prime is 18186137. The next prime is 18186151. The reversal of 18186139 is 93168181.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 93168181 = 7907 ⋅11783.

It is a cyclic number.

It is not a de Polignac number, because 18186139 - 2¹ = 18186137 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18186098 and 18186107.

It is not an unprimeable number, because it can be changed into a prime (18186137) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22987 + ... + 23764.

It is an arithmetic number, because the mean of its divisors is an integer number (4558320).

Almost surely, 2^18186139 is an apocalyptic number.

18186139 is a deficient number, since it is larger than the sum of its proper divisors (47141).

18186139 is an equidigital number, since it uses as much as digits as its factorization.

18186139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47140.

The product of its digits is 10368, while the sum is 37.

The square root of 18186139 is about 4264.5209578568. The cubic root of 18186139 is about 262.9744176517.

It can be divided in two parts, 181 and 86139, that added together give a triangular number (86320 = T₄₁₅).

The spelling of 18186139 in words is "eighteen million, one hundred eighty-six thousand, one hundred thirty-nine".