18439936 has 18 divisors (see below), whose sum is σ = 36808352. Its totient is φ = 9219840.

The previous prime is 18439921. The next prime is 18439961. The reversal of 18439936 is 63993481.

It is a junction number, because it is equal to n+sod(n) for n = 18439892 and 18439901.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35760 + ... + 36271.

Almost surely, 2^18439936 is an apocalyptic number.

18439936 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

18439936 is a deficient number, since it is larger than the sum of its proper divisors (18368416).

18439936 is an frugal number, since it uses more digits than its factorization.

18439936 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72047 (or 72033 counting only the distinct ones).

The product of its digits is 139968, while the sum is 43.

The square root of 18439936 is about 4294.1746587674. The cubic root of 18439936 is about 264.1920854885.

The spelling of 18439936 in words is "eighteen million, four hundred thirty-nine thousand, nine hundred thirty-six".