21595369 has 2 divisors, whose sum is σ = 21595370. Its totient is φ = 21595368.

The previous prime is 21595351. The next prime is 21595391. The reversal of 21595369 is 96359512.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20820969 + 774400 = 4563^2 + 880^2 .

It is a cyclic number.

It is not a de Polignac number, because 21595369 - 2⁷ = 21595241 is a prime.

It is a super-2 number, since 2×21595369² = 932719924492322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21595319) 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, 10797684 + 10797685.

It is an arithmetic number, because the mean of its divisors is an integer number (10797685).

Almost surely, 2^21595369 is an apocalyptic number.

It is an amenable number.

21595369 is a deficient number, since it is larger than the sum of its proper divisors (1).

21595369 is an equidigital number, since it uses as much as digits as its factorization.

21595369 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 72900, while the sum is 40.

The square root of 21595369 is about 4647.0817724675. The cubic root of 21595369 is about 278.4754256332.

The spelling of 21595369 in words is "twenty-one million, five hundred ninety-five thousand, three hundred sixty-nine".