21365269 has 2 divisors, whose sum is σ = 21365270. Its totient is φ = 21365268.

The previous prime is 21365233. The next prime is 21365299. The reversal of 21365269 is 96256312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20133169 + 1232100 = 4487^2 + 1110^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21365269 is a prime.

It is a super-2 number, since 2×21365269² = 912949438884722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21365219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10682634 + 10682635.

It is an arithmetic number, because the mean of its divisors is an integer number (10682635).

Almost surely, 2^21365269 is an apocalyptic number.

It is an amenable number.

21365269 is a deficient number, since it is larger than the sum of its proper divisors (1).

21365269 is an equidigital number, since it uses as much as digits as its factorization.

21365269 is an evil number, because the sum of its binary digits is even.

The product of its digits is 19440, while the sum is 34.

The square root of 21365269 is about 4622.2579979919. The cubic root of 21365269 is about 277.4828342059.

The spelling of 21365269 in words is "twenty-one million, three hundred sixty-five thousand, two hundred sixty-nine".