18839920 has 80 divisors (see below), whose sum is σ = 48568320. Its totient is φ = 6739200.

The previous prime is 18839917. The next prime is 18839923. The reversal of 18839920 is 2993881.

It is an interprime number because it is at equal distance from previous prime (18839917) and next prime (18839923).

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18839923) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 69385 + ... + 69655.

It is an arithmetic number, because the mean of its divisors is an integer number (607104).

Almost surely, 2^18839920 is an apocalyptic number.

18839920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18839920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24284160).

18839920 is an abundant number, since it is smaller than the sum of its proper divisors (29728400).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18839920 is a wasteful number, since it uses less digits than its factorization.

18839920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 374 (or 368 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 40.

The square root of 18839920 is about 4340.4976673188. The cubic root of 18839920 is about 266.0886507992.

It can be divided in two parts, 18 and 839920, that added together give a palindrome (839938).

The spelling of 18839920 in words is "eighteen million, eight hundred thirty-nine thousand, nine hundred twenty".