18216198 has 128 divisors (see below), whose sum is σ = 54512640. Its totient is φ = 4354560.

The previous prime is 18216181. The next prime is 18216221. The reversal of 18216198 is 89161281.

18216198 is a `hidden beast` number, since 18 + 21 + 619 + 8 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 53886 + ... + 54222.

It is an arithmetic number, because the mean of its divisors is an integer number (425880).

Almost surely, 2^18216198 is an apocalyptic number.

18216198 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 18216198, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27256320).

18216198 is an abundant number, since it is smaller than the sum of its proper divisors (36296442).

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

18216198 is a wasteful number, since it uses less digits than its factorization.

18216198 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 379 (or 373 counting only the distinct ones).

The product of its digits is 6912, while the sum is 36.

The square root of 18216198 is about 4268.0438142081. The cubic root of 18216198 is about 263.1192238488.

The spelling of 18216198 in words is "eighteen million, two hundred sixteen thousand, one hundred ninety-eight".