21818227 has 2 divisors, whose sum is σ = 21818228. Its totient is φ = 21818226.

The previous prime is 21818221. The next prime is 21818267. The reversal of 21818227 is 72281812.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21818227 - 2¹⁹ = 21293939 is a prime.

It is not a weakly prime, because it can be changed into another prime (21818221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10909113 + 10909114.

It is an arithmetic number, because the mean of its divisors is an integer number (10909114).

Almost surely, 2^21818227 is an apocalyptic number.

21818227 is a deficient number, since it is larger than the sum of its proper divisors (1).

21818227 is an equidigital number, since it uses as much as digits as its factorization.

21818227 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3584, while the sum is 31.

The square root of 21818227 is about 4670.9985013913. The cubic root of 21818227 is about 279.4300779923.

The spelling of 21818227 in words is "twenty-one million, eight hundred eighteen thousand, two hundred twenty-seven".