21616228 has 12 divisors (see below), whose sum is σ = 39473280. Its totient is φ = 10338152.

The previous prime is 21616213. The next prime is 21616237. The reversal of 21616228 is 82261612.

It is a super-2 number, since 2×21616228² = 934522625895968, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21616196 and 21616205.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 117388 + ... + 117571.

It is an arithmetic number, because the mean of its divisors is an integer number (3289440).

Almost surely, 2^21616228 is an apocalyptic number.

It is an amenable number.

21616228 is a deficient number, since it is larger than the sum of its proper divisors (17857052).

21616228 is a wasteful number, since it uses less digits than its factorization.

21616228 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 234986 (or 234984 counting only the distinct ones).

The product of its digits is 2304, while the sum is 28.

The square root of 21616228 is about 4649.3255424846. The cubic root of 21616228 is about 278.5650567279.

The spelling of 21616228 in words is "twenty-one million, six hundred sixteen thousand, two hundred twenty-eight".