21799589 has 16 divisors (see below), whose sum is σ = 25792128. Its totient is φ = 18038592.

The previous prime is 21799567. The next prime is 21799597. The reversal of 21799589 is 98599712.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21799589 is a prime.

It is a Smith number, since the sum of its digits (50) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21799529) 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 in 15 ways as a sum of consecutive naturals, for example, 24419 + ... + 25295.

It is an arithmetic number, because the mean of its divisors is an integer number (1612008).

Almost surely, 2^21799589 is an apocalyptic number.

It is an amenable number.

21799589 is a deficient number, since it is larger than the sum of its proper divisors (3992539).

21799589 is an equidigital number, since it uses as much as digits as its factorization.

21799589 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1004.

The product of its digits is 408240, while the sum is 50.

The square root of 21799589 is about 4669.0029984998. The cubic root of 21799589 is about 279.3504885515.

The spelling of 21799589 in words is "twenty-one million, seven hundred ninety-nine thousand, five hundred eighty-nine".