21338889 has 16 divisors (see below), whose sum is σ = 33426624. Its totient is φ = 11937600.

The previous prime is 21338873. The next prime is 21338929. The reversal of 21338889 is 98883312.

It is not a de Polignac number, because 21338889 - 2⁴ = 21338873 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21338889.

It is not an unprimeable number, because it can be changed into a prime (21338189) 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, 24442 + ... + 25299.

It is an arithmetic number, because the mean of its divisors is an integer number (2089164).

Almost surely, 2^21338889 is an apocalyptic number.

It is an amenable number.

21338889 is a deficient number, since it is larger than the sum of its proper divisors (12087735).

21338889 is a wasteful number, since it uses less digits than its factorization.

21338889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49768.

The product of its digits is 82944, while the sum is 42.

The square root of 21338889 is about 4619.4035329250. The cubic root of 21338889 is about 277.3685831764.

The spelling of 21338889 in words is "twenty-one million, three hundred thirty-eight thousand, eight hundred eighty-nine".