18865920 has 144 divisors (see below), whose sum is σ = 64018080. Its totient is φ = 4734976.

The previous prime is 18865909. The next prime is 18865939. The reversal of 18865920 is 2956881.

It is a Saint-Exupery number, since it is equal to the product of the sides of a Pythagorean triangle: 340 × 204 × 272.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 1109752 + ... + 1109768.

It is an arithmetic number, because the mean of its divisors is an integer number (444570).

Almost surely, 2^18865920 is an apocalyptic number.

18865920 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 18865920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32009040).

18865920 is an abundant number, since it is smaller than the sum of its proper divisors (45152160).

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

18865920 is an frugal number, since it uses more digits than its factorization.

18865920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75 (or 27 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 39.

The square root of 18865920 is about 4343.4916829666. The cubic root of 18865920 is about 266.2109995995.

The spelling of 18865920 in words is "eighteen million, eight hundred sixty-five thousand, nine hundred twenty".