18139539 has 8 divisors (see below), whose sum is σ = 26384832. Its totient is φ = 10993640.

The previous prime is 18139531. The next prime is 18139543. The reversal of 18139539 is 93593181.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18139539 - 2³ = 18139531 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18139497 and 18139506.

It is not an unprimeable number, because it can be changed into a prime (18139531) 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 7 ways as a sum of consecutive naturals, for example, 274809 + ... + 274874.

It is an arithmetic number, because the mean of its divisors is an integer number (3298104).

Almost surely, 2^18139539 is an apocalyptic number.

18139539 is a deficient number, since it is larger than the sum of its proper divisors (8245293).

18139539 is a wasteful number, since it uses less digits than its factorization.

18139539 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 549697.

The product of its digits is 29160, while the sum is 39.

The square root of 18139539 is about 4259.0537681509. The cubic root of 18139539 is about 262.7496110958.

The spelling of 18139539 in words is "eighteen million, one hundred thirty-nine thousand, five hundred thirty-nine".