18304020 has 144 divisors (see below), whose sum is σ = 64646400. Its totient is φ = 4105728.

The previous prime is 18303979. The next prime is 18304031. The reversal of 18304020 is 2040381.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 18303984 and 18304002.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 91881 + ... + 92079.

Almost surely, 2^18304020 is an apocalyptic number.

18304020 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 18304020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32323200).

18304020 is an abundant number, since it is smaller than the sum of its proper divisors (46342380).

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

18304020 is a wasteful number, since it uses less digits than its factorization.

18304020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 294 (or 289 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 18304020 is about 4278.3197636455. The cubic root of 18304020 is about 263.5413869679.

The spelling of 18304020 in words is "eighteen million, three hundred four thousand, twenty".