18039231 has 24 divisors (see below), whose sum is σ = 30476160. Its totient is φ = 10066896.

The previous prime is 18039209. The next prime is 18039233. The reversal of 18039231 is 13293081.

It is not a de Polignac number, because 18039231 - 2⁶ = 18039167 is a prime.

It is a super-2 number, since 2×18039231² = 650827710142722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 18039195 and 18039204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18039233) by changing a digit.

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 in 23 ways as a sum of consecutive naturals, for example, 621 + ... + 6038.

It is an arithmetic number, because the mean of its divisors is an integer number (1269840).

Almost surely, 2^18039231 is an apocalyptic number.

18039231 is a deficient number, since it is larger than the sum of its proper divisors (12436929).

18039231 is a wasteful number, since it uses less digits than its factorization.

18039231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6715 (or 6712 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 18039231 is about 4247.2615883649. The cubic root of 18039231 is about 262.2643981271.

The spelling of 18039231 in words is "eighteen million, thirty-nine thousand, two hundred thirty-one".