21360289 has 2 divisors, whose sum is σ = 21360290. Its totient is φ = 21360288.

The previous prime is 21360281. The next prime is 21360319. The reversal of 21360289 is 98206312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15681600 + 5678689 = 3960^2 + 2383^2 .

It is a cyclic number.

It is not a de Polignac number, because 21360289 - 2³ = 21360281 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21360289.

It is not a weakly prime, because it can be changed into another prime (21360281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10680144 + 10680145.

It is an arithmetic number, because the mean of its divisors is an integer number (10680145).

Almost surely, 2^21360289 is an apocalyptic number.

It is an amenable number.

21360289 is a deficient number, since it is larger than the sum of its proper divisors (1).

21360289 is an equidigital number, since it uses as much as digits as its factorization.

21360289 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5184, while the sum is 31.

The square root of 21360289 is about 4621.7192688436. The cubic root of 21360289 is about 277.4612731716.

The spelling of 21360289 in words is "twenty-one million, three hundred sixty thousand, two hundred eighty-nine".