21231269 has 2 divisors, whose sum is σ = 21231270. Its totient is φ = 21231268.

The previous prime is 21231253. The next prime is 21231307. The reversal of 21231269 is 96213212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19936225 + 1295044 = 4465^2 + 1138^2 .

It is a cyclic number.

It is not a de Polignac number, because 21231269 - 2⁴ = 21231253 is a prime.

It is a super-2 number, since 2×21231269² = 901533566700722, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21233269) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10615634 + 10615635.

It is an arithmetic number, because the mean of its divisors is an integer number (10615635).

Almost surely, 2^21231269 is an apocalyptic number.

It is an amenable number.

21231269 is a deficient number, since it is larger than the sum of its proper divisors (1).

21231269 is an equidigital number, since it uses as much as digits as its factorization.

21231269 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1296, while the sum is 26.

The square root of 21231269 is about 4607.7401185397. The cubic root of 21231269 is about 276.9015059033.

The spelling of 21231269 in words is "twenty-one million, two hundred thirty-one thousand, two hundred sixty-nine".