18985720 has 64 divisors (see below), whose sum is σ = 47628000. Its totient is φ = 6763008.

The previous prime is 18985717. The next prime is 18985721. The reversal of 18985720 is 2758981.

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 (18985721) 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, 14451 + ... + 15709.

Almost surely, 2^18985720 is an apocalyptic number.

18985720 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 18985720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23814000).

18985720 is an abundant number, since it is smaller than the sum of its proper divisors (28642280).

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

18985720 is a wasteful number, since it uses less digits than its factorization.

18985720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1312 (or 1308 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 40.

The square root of 18985720 is about 4357.2606073082. The cubic root of 18985720 is about 266.7732976340.

The spelling of 18985720 in words is "eighteen million, nine hundred eighty-five thousand, seven hundred twenty".