21513269 has 2 divisors, whose sum is σ = 21513270. Its totient is φ = 21513268.

The previous prime is 21513259. The next prime is 21513277. The reversal of 21513269 is 96231512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14554225 + 6959044 = 3815^2 + 2638^2 .

It is a cyclic number.

It is not a de Polignac number, because 21513269 - 2⁴ = 21513253 is a prime.

It is a super-2 number, since 2×21513269² = 925641486132722, which contains 22 as substring.

It is equal to p_1360379 and since 21513269 and 1360379 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21513209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10756634 + 10756635.

It is an arithmetic number, because the mean of its divisors is an integer number (10756635).

Almost surely, 2^21513269 is an apocalyptic number.

It is an amenable number.

21513269 is a deficient number, since it is larger than the sum of its proper divisors (1).

21513269 is an equidigital number, since it uses as much as digits as its factorization.

21513269 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3240, while the sum is 29.

The square root of 21513269 is about 4638.2398601194. The cubic root of 21513269 is about 278.1220803296.

The spelling of 21513269 in words is "twenty-one million, five hundred thirteen thousand, two hundred sixty-nine".