21798228 has 48 divisors (see below), whose sum is σ = 52399424. Its totient is φ = 7050240.

The previous prime is 21798221. The next prime is 21798241. The reversal of 21798228 is 82289712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21798221) 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, 70851 + ... + 71157.

Almost surely, 2^21798228 is an apocalyptic number.

It is an amenable number.

21798228 is an abundant number, since it is smaller than the sum of its proper divisors (30601196).

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

21798228 is a wasteful number, since it uses less digits than its factorization.

21798228 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 472 (or 470 counting only the distinct ones).

The product of its digits is 32256, while the sum is 39.

The square root of 21798228 is about 4668.8572477642. The cubic root of 21798228 is about 279.3446749261.

The spelling of 21798228 in words is "twenty-one million, seven hundred ninety-eight thousand, two hundred twenty-eight".