18232139 has 4 divisors (see below), whose sum is σ = 18251424. Its totient is φ = 18212856.

The previous prime is 18232127. The next prime is 18232141. The reversal of 18232139 is 93123281.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 93123281 = 89 ⋅1046329.

It is a cyclic number.

It is not a de Polignac number, because 18232139 - 2⁸ = 18231883 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18232199) 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, 8147 + ... + 10140.

It is an arithmetic number, because the mean of its divisors is an integer number (4562856).

Almost surely, 2^18232139 is an apocalyptic number.

18232139 is a deficient number, since it is larger than the sum of its proper divisors (19285).

18232139 is an equidigital number, since it uses as much as digits as its factorization.

18232139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19284.

The product of its digits is 2592, while the sum is 29.

The square root of 18232139 is about 4269.9108889999. The cubic root of 18232139 is about 263.1959533735.

The spelling of 18232139 in words is "eighteen million, two hundred thirty-two thousand, one hundred thirty-nine".