21135227 has 2 divisors, whose sum is σ = 21135228. Its totient is φ = 21135226.

The previous prime is 21135223. The next prime is 21135259. The reversal of 21135227 is 72253112.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21135227 - 2² = 21135223 is a prime.

It is not a weakly prime, because it can be changed into another prime (21135223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10567613 + 10567614.

It is an arithmetic number, because the mean of its divisors is an integer number (10567614).

Almost surely, 2^21135227 is an apocalyptic number.

21135227 is a deficient number, since it is larger than the sum of its proper divisors (1).

21135227 is an equidigital number, since it uses as much as digits as its factorization.

21135227 is an evil number, because the sum of its binary digits is even.

The product of its digits is 840, while the sum is 23.

The square root of 21135227 is about 4597.3064940245. The cubic root of 21135227 is about 276.4833431755.

Adding to 21135227 its reverse (72253112), we get a palindrome (93388339).

The spelling of 21135227 in words is "twenty-one million, one hundred thirty-five thousand, two hundred twenty-seven".