18972798 has 32 divisors (see below), whose sum is σ = 41395200. Its totient is φ = 5762016.

The previous prime is 18972797. The next prime is 18972817. The reversal of 18972798 is 89727981.

It is a self number, because there is not a number n which added to its sum of digits gives 18972798.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18972797) 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, 4623 + ... + 7701.

It is an arithmetic number, because the mean of its divisors is an integer number (1293600).

Almost surely, 2^18972798 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18972798, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20697600).

18972798 is an abundant number, since it is smaller than the sum of its proper divisors (22422402).

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

18972798 is a wasteful number, since it uses less digits than its factorization.

18972798 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3176.

The product of its digits is 508032, while the sum is 51.

The square root of 18972798 is about 4355.7775425290. Note that the first 3 decimals coincide. The cubic root of 18972798 is about 266.7127604349.

The spelling of 18972798 in words is "eighteen million, nine hundred seventy-two thousand, seven hundred ninety-eight".