21417269 has 2 divisors, whose sum is σ = 21417270. Its totient is φ = 21417268.

The previous prime is 21417257. The next prime is 21417271. The reversal of 21417269 is 96271412.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11992369 + 9424900 = 3463^2 + 3070^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21417269 is a prime.

It is a super-2 number, since 2×21417269² = 917398822836722, which contains 22 as substring.

Together with 21417271, 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 (21417239) 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, 10708634 + 10708635.

It is an arithmetic number, because the mean of its divisors is an integer number (10708635).

Almost surely, 2^21417269 is an apocalyptic number.

It is an amenable number.

21417269 is a deficient number, since it is larger than the sum of its proper divisors (1).

21417269 is an equidigital number, since it uses as much as digits as its factorization.

21417269 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6048, while the sum is 32.

The square root of 21417269 is about 4627.8795360294. The cubic root of 21417269 is about 277.7077696226.

The spelling of 21417269 in words is "twenty-one million, four hundred seventeen thousand, two hundred sixty-nine".