21814229 has 2 divisors, whose sum is σ = 21814230. Its totient is φ = 21814228.

The previous prime is 21814187. The next prime is 21814231. The reversal of 21814229 is 92241812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21808900 + 5329 = 4670^2 + 73^2 .

It is a cyclic number.

It is not a de Polignac number, because 21814229 - 2⁸ = 21813973 is a prime.

Together with 21814231, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21814249) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10907114 + 10907115.

It is an arithmetic number, because the mean of its divisors is an integer number (10907115).

Almost surely, 2^21814229 is an apocalyptic number.

It is an amenable number.

21814229 is a deficient number, since it is larger than the sum of its proper divisors (1).

21814229 is an equidigital number, since it uses as much as digits as its factorization.

21814229 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2304, while the sum is 29.

The square root of 21814229 is about 4670.5705218956. The cubic root of 21814229 is about 279.4130092407.

The spelling of 21814229 in words is "twenty-one million, eight hundred fourteen thousand, two hundred twenty-nine".