21703589 has 2 divisors, whose sum is σ = 21703590. Its totient is φ = 21703588.

The previous prime is 21703579. The next prime is 21703601. The reversal of 21703589 is 98530712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11730625 + 9972964 = 3425^2 + 3158^2 .

It is a cyclic number.

It is not a de Polignac number, because 21703589 - 2⁴ = 21703573 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21703579) 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, 10851794 + 10851795.

It is an arithmetic number, because the mean of its divisors is an integer number (10851795).

Almost surely, 2^21703589 is an apocalyptic number.

It is an amenable number.

21703589 is a deficient number, since it is larger than the sum of its proper divisors (1).

21703589 is an equidigital number, since it uses as much as digits as its factorization.

21703589 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15120, while the sum is 35.

The square root of 21703589 is about 4658.7110878439. The cubic root of 21703589 is about 278.9398216410.

The spelling of 21703589 in words is "twenty-one million, seven hundred three thousand, five hundred eighty-nine".