21275227 has 4 divisors (see below), whose sum is σ = 21410896. Its totient is φ = 21139560.

The previous prime is 21275209. The next prime is 21275237. The reversal of 21275227 is 72257212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21275227 - 2⁷ = 21275099 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21275195 and 21275204.

It is not an unprimeable number, because it can be changed into a prime (21275237) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 67599 + ... + 67912.

It is an arithmetic number, because the mean of its divisors is an integer number (5352724).

Almost surely, 2^21275227 is an apocalyptic number.

21275227 is a deficient number, since it is larger than the sum of its proper divisors (135669).

21275227 is a wasteful number, since it uses less digits than its factorization.

21275227 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135668.

The product of its digits is 3920, while the sum is 28.

The square root of 21275227 is about 4612.5076693703. The cubic root of 21275227 is about 277.0924765194.

The spelling of 21275227 in words is "twenty-one million, two hundred seventy-five thousand, two hundred twenty-seven".