21255198 has 16 divisors (see below), whose sum is σ = 42562560. Its totient is φ = 7076376.

The previous prime is 21255161. The next prime is 21255203. The reversal of 21255198 is 89155212.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4893 + ... + 8151.

It is an arithmetic number, because the mean of its divisors is an integer number (2660160).

Almost surely, 2^21255198 is an apocalyptic number.

21255198 is an abundant number, since it is smaller than the sum of its proper divisors (21307362).

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

21255198 is a wasteful number, since it uses less digits than its factorization.

21255198 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4351.

The product of its digits is 7200, while the sum is 33.

The square root of 21255198 is about 4610.3359964324. The cubic root of 21255198 is about 277.0054954229.

The spelling of 21255198 in words is "twenty-one million, two hundred fifty-five thousand, one hundred ninety-eight".