21590369 has 2 divisors, whose sum is σ = 21590370. Its totient is φ = 21590368.

The previous prime is 21590339. The next prime is 21590411. The reversal of 21590369 is 96309512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20566225 + 1024144 = 4535^2 + 1012^2 .

It is a cyclic number.

It is not a de Polignac number, because 21590369 - 2⁸ = 21590113 is a prime.

It is a super-2 number, since 2×21590369² = 932288067112322, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21590329) 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, 10795184 + 10795185.

It is an arithmetic number, because the mean of its divisors is an integer number (10795185).

Almost surely, 2^21590369 is an apocalyptic number.

It is an amenable number.

21590369 is a deficient number, since it is larger than the sum of its proper divisors (1).

21590369 is an equidigital number, since it uses as much as digits as its factorization.

21590369 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 14580, while the sum is 35.

The square root of 21590369 is about 4646.5437692978. The cubic root of 21590369 is about 278.4539320651.

The spelling of 21590369 in words is "twenty-one million, five hundred ninety thousand, three hundred sixty-nine".