21270269 has 2 divisors, whose sum is σ = 21270270. Its totient is φ = 21270268.

The previous prime is 21270233. The next prime is 21270299. The reversal of 21270269 is 96207212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16297369 + 4972900 = 4037^2 + 2230^2 .

It is a cyclic number.

It is not a de Polignac number, because 21270269 - 2¹² = 21266173 is a prime.

It is a super-2 number, since 2×21270269² = 904848686664722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21270299) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10635134 + 10635135.

It is an arithmetic number, because the mean of its divisors is an integer number (10635135).

Almost surely, 2^21270269 is an apocalyptic number.

It is an amenable number.

21270269 is a deficient number, since it is larger than the sum of its proper divisors (1).

21270269 is an equidigital number, since it uses as much as digits as its factorization.

21270269 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3024, while the sum is 29.

The square root of 21270269 is about 4611.9701863737. The cubic root of 21270269 is about 277.0709502120.

The spelling of 21270269 in words is "twenty-one million, two hundred seventy thousand, two hundred sixty-nine".