21616227 has 10 divisors (see below), whose sum is σ = 32291028. Its totient is φ = 14410764.

The previous prime is 21616213. The next prime is 21616237. The reversal of 21616227 is 72261612.

21616227 is a `hidden beast` number, since 21 + 616 + 2 + 27 = 666.

It is not a de Polignac number, because 21616227 - 2⁴ = 21616211 is a prime.

It is a super-2 number, since 2×21616227² = 934522539431058, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a self number, because there is not a number n which added to its sum of digits gives 21616227.

It is not an unprimeable number, because it can be changed into a prime (21616237) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 133353 + ... + 133514.

Almost surely, 2^21616227 is an apocalyptic number.

21616227 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

21616227 is a deficient number, since it is larger than the sum of its proper divisors (10674801).

21616227 is an equidigital number, since it uses as much as digits as its factorization.

21616227 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 266879 (or 266870 counting only the distinct ones).

The product of its digits is 2016, while the sum is 27.

The square root of 21616227 is about 4649.3254349421. The cubic root of 21616227 is about 278.5650524323.

Adding to 21616227 its reverse (72261612), we get a palindrome (93877839).

The spelling of 21616227 in words is "twenty-one million, six hundred sixteen thousand, two hundred twenty-seven".