18520320 has 288 divisors, whose sum is σ = 74172672. Its totient is φ = 3833856.

The previous prime is 18520291. The next prime is 18520321. The reversal of 18520320 is 2302581.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18520321) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 349414 + ... + 349466.

It is an arithmetic number, because the mean of its divisors is an integer number (257544).

Almost surely, 2^18520320 is an apocalyptic number.

18520320 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 18520320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37086336).

18520320 is an abundant number, since it is smaller than the sum of its proper divisors (55652352).

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

18520320 is a wasteful number, since it uses less digits than its factorization.

18520320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97 (or 83 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 18520320 is about 4303.5241372624. The cubic root of 18520320 is about 264.5754207373.

The spelling of 18520320 in words is "eighteen million, five hundred twenty thousand, three hundred twenty".