21136369 has 2 divisors, whose sum is σ = 21136370. Its totient is φ = 21136368.

The previous prime is 21136319. The next prime is 21136393. The reversal of 21136369 is 96363112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13601344 + 7535025 = 3688^2 + 2745^2 .

It is a cyclic number.

It is not a de Polignac number, because 21136369 - 2⁹ = 21135857 is a prime.

It is a super-2 number, since 2×21136369² = 893492189008322, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21136369.

It is not a weakly prime, because it can be changed into another prime (21136319) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10568184 + 10568185.

It is an arithmetic number, because the mean of its divisors is an integer number (10568185).

Almost surely, 2^21136369 is an apocalyptic number.

It is an amenable number.

21136369 is a deficient number, since it is larger than the sum of its proper divisors (1).

21136369 is an equidigital number, since it uses as much as digits as its factorization.

21136369 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5832, while the sum is 31.

The square root of 21136369 is about 4597.4306955081. The cubic root of 21136369 is about 276.4883228285.

The spelling of 21136369 in words is "twenty-one million, one hundred thirty-six thousand, three hundred sixty-nine".