18088639 has 4 divisors (see below), whose sum is σ = 18131040. Its totient is φ = 18046240.

The previous prime is 18088621. The next prime is 18088643. The reversal of 18088639 is 93688081.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 18088639 - 2⁵ = 18088607 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18088595 and 18088604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18088619) 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 3 ways as a sum of consecutive naturals, for example, 20554 + ... + 21415.

It is an arithmetic number, because the mean of its divisors is an integer number (4532760).

Almost surely, 2^18088639 is an apocalyptic number.

18088639 is a deficient number, since it is larger than the sum of its proper divisors (42401).

18088639 is an equidigital number, since it uses as much as digits as its factorization.

18088639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42400.

The product of its (nonzero) digits is 82944, while the sum is 43.

The square root of 18088639 is about 4253.0740647207. The cubic root of 18088639 is about 262.5036202071.

The spelling of 18088639 in words is "eighteen million, eighty-eight thousand, six hundred thirty-nine".