21338789 has 4 divisors (see below), whose sum is σ = 21361824. Its totient is φ = 21315756.

The previous prime is 21338783. The next prime is 21338797. The reversal of 21338789 is 98783312.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21338789 - 2⁸ = 21338533 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21338783) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10067 + ... + 12000.

It is an arithmetic number, because the mean of its divisors is an integer number (5340456).

Almost surely, 2^21338789 is an apocalyptic number.

It is an amenable number.

21338789 is a deficient number, since it is larger than the sum of its proper divisors (23035).

21338789 is an equidigital number, since it uses as much as digits as its factorization.

21338789 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23034.

The product of its digits is 72576, while the sum is 41.

The square root of 21338789 is about 4619.3927090041. The cubic root of 21338789 is about 277.3681499001.

The spelling of 21338789 in words is "twenty-one million, three hundred thirty-eight thousand, seven hundred eighty-nine".