18998280 has 192 divisors, whose sum is σ = 73872000. Its totient is φ = 4330368.

The previous prime is 18998249. The next prime is 18998281. The reversal of 18998280 is 8289981.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (18998281) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 52741 + ... + 53099.

It is an arithmetic number, because the mean of its divisors is an integer number (384750).

Almost surely, 2^18998280 is an apocalyptic number.

18998280 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 18998280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36936000).

18998280 is an abundant number, since it is smaller than the sum of its proper divisors (54873720).

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

18998280 is a wasteful number, since it uses less digits than its factorization.

18998280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 393 (or 376 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 45.

The square root of 18998280 is about 4358.7016415442. The cubic root of 18998280 is about 266.8321126102.

The spelling of 18998280 in words is "eighteen million, nine hundred ninety-eight thousand, two hundred eighty".