21855227 has 2 divisors, whose sum is σ = 21855228. Its totient is φ = 21855226.

The previous prime is 21855209. The next prime is 21855233. The reversal of 21855227 is 72255812.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21855227 - 2¹⁸ = 21593083 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 21855193 and 21855202.

It is not a weakly prime, because it can be changed into another prime (21855277) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10927613 + 10927614.

It is an arithmetic number, because the mean of its divisors is an integer number (10927614).

Almost surely, 2^21855227 is an apocalyptic number.

21855227 is a deficient number, since it is larger than the sum of its proper divisors (1).

21855227 is an equidigital number, since it uses as much as digits as its factorization.

21855227 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11200, while the sum is 32.

The square root of 21855227 is about 4674.9574329613. The cubic root of 21855227 is about 279.5879440744.

The spelling of 21855227 in words is "twenty-one million, eight hundred fifty-five thousand, two hundred twenty-seven".