21108227 has 16 divisors (see below), whose sum is σ = 25766400. Its totient is φ = 16898112.

The previous prime is 21108209. The next prime is 21108233. The reversal of 21108227 is 72280112.

It is not a de Polignac number, because 21108227 - 2⁶ = 21108163 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21108277) 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, 5399 + ... + 8447.

It is an arithmetic number, because the mean of its divisors is an integer number (1610400).

Almost surely, 2^21108227 is an apocalyptic number.

21108227 is a deficient number, since it is larger than the sum of its proper divisors (4658173).

21108227 is a wasteful number, since it uses less digits than its factorization.

21108227 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3122.

The product of its (nonzero) digits is 448, while the sum is 23.

The square root of 21108227 is about 4594.3690535263. The cubic root of 21108227 is about 276.3655582823.

Adding to 21108227 its reverse (72280112), we get a palindrome (93388339).

The spelling of 21108227 in words is "twenty-one million, one hundred eight thousand, two hundred twenty-seven".