18439839 has 32 divisors (see below), whose sum is σ = 30458880. Its totient is φ = 10929600.

The previous prime is 18439831. The next prime is 18439847. The reversal of 18439839 is 93893481.

It is an interprime number because it is at equal distance from previous prime (18439831) and next prime (18439847).

It is not a de Polignac number, because 18439839 - 2³ = 18439831 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18439794 and 18439803.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18439831) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13299 + ... + 14619.

It is an arithmetic number, because the mean of its divisors is an integer number (951840).

Almost surely, 2^18439839 is an apocalyptic number.

18439839 is a deficient number, since it is larger than the sum of its proper divisors (12019041).

18439839 is a wasteful number, since it uses less digits than its factorization.

18439839 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1388 (or 1382 counting only the distinct ones).

The product of its digits is 186624, while the sum is 45.

The square root of 18439839 is about 4294.1633643819. The cubic root of 18439839 is about 264.1916222425.

The spelling of 18439839 in words is "eighteen million, four hundred thirty-nine thousand, eight hundred thirty-nine".