18913720 has 64 divisors (see below), whose sum is σ = 50227200. Its totient is φ = 6272640.

The previous prime is 18913717. The next prime is 18913733. The reversal of 18913720 is 2731981.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7591 + ... + 9769.

It is an arithmetic number, because the mean of its divisors is an integer number (784800).

Almost surely, 2^18913720 is an apocalyptic number.

18913720 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 18913720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25113600).

18913720 is an abundant number, since it is smaller than the sum of its proper divisors (31313480).

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

18913720 is a wasteful number, since it uses less digits than its factorization.

18913720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2228 (or 2224 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 31.

The square root of 18913720 is about 4348.9906875044. The cubic root of 18913720 is about 266.4356401859.

The spelling of 18913720 in words is "eighteen million, nine hundred thirteen thousand, seven hundred twenty".