21262229 has 2 divisors, whose sum is σ = 21262230. Its totient is φ = 21262228.

The previous prime is 21262211. The next prime is 21262237. The reversal of 21262229 is 92226212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20232004 + 1030225 = 4498^2 + 1015^2 .

It is a cyclic number.

It is not a de Polignac number, because 21262229 - 2⁸ = 21261973 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21262198 and 21262207.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21262289) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10631114 + 10631115.

It is an arithmetic number, because the mean of its divisors is an integer number (10631115).

Almost surely, 2^21262229 is an apocalyptic number.

It is an amenable number.

21262229 is a deficient number, since it is larger than the sum of its proper divisors (1).

21262229 is an equidigital number, since it uses as much as digits as its factorization.

21262229 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1728, while the sum is 26.

The square root of 21262229 is about 4611.0984591527. The cubic root of 21262229 is about 277.0360355748.

The spelling of 21262229 in words is "twenty-one million, two hundred sixty-two thousand, two hundred twenty-nine".