18989520 has 80 divisors (see below), whose sum is σ = 64228032. Its totient is φ = 4602880.

The previous prime is 18989507. The next prime is 18989533. The reversal of 18989520 is 2598981.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (18989507) and next prime (18989533).

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

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, 957 + ... + 6236.

Almost surely, 2^18989520 is an apocalyptic number.

18989520 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 18989520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32114016).

18989520 is an abundant number, since it is smaller than the sum of its proper divisors (45238512).

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

18989520 is a wasteful number, since it uses less digits than its factorization.

18989520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7220 (or 7214 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 42.

The square root of 18989520 is about 4357.6966392809. The cubic root of 18989520 is about 266.7910947100.

The spelling of 18989520 in words is "eighteen million, nine hundred eighty-nine thousand, five hundred twenty".