21797589 has 16 divisors (see below), whose sum is σ = 32800320. Its totient is φ = 12754560.

The previous prime is 21797569. The next prime is 21797591. The reversal of 21797589 is 98579712.

It is not a de Polignac number, because 21797589 - 2¹¹ = 21795541 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21797569) 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 in 15 ways as a sum of consecutive naturals, for example, 10432 + ... + 12345.

It is an arithmetic number, because the mean of its divisors is an integer number (2050020).

Almost surely, 2^21797589 is an apocalyptic number.

21797589 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

21797589 is a deficient number, since it is larger than the sum of its proper divisors (11002731).

21797589 is a wasteful number, since it uses less digits than its factorization.

21797589 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22820.

The product of its digits is 317520, while the sum is 48.

The square root of 21797589 is about 4668.7888150997. The cubic root of 21797589 is about 279.3419453007.

The spelling of 21797589 in words is "twenty-one million, seven hundred ninety-seven thousand, five hundred eighty-nine".