21869128 has 16 divisors (see below), whose sum is σ = 41171760. Its totient is φ = 10890000.

The previous prime is 21869119. The next prime is 21869129. The reversal of 21869128 is 82196812.

It is not an unprimeable number, because it can be changed into a prime (21869129) 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 3 ways as a sum of consecutive naturals, for example, 3438 + ... + 7453.

It is an arithmetic number, because the mean of its divisors is an integer number (2573235).

Almost surely, 2^21869128 is an apocalyptic number.

It is an amenable number.

21869128 is a deficient number, since it is larger than the sum of its proper divisors (19302632).

21869128 is a wasteful number, since it uses less digits than its factorization.

21869128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11148 (or 11144 counting only the distinct ones).

The product of its digits is 13824, while the sum is 37.

The square root of 21869128 is about 4676.4439481298. The cubic root of 21869128 is about 279.6472087419.

The spelling of 21869128 in words is "twenty-one million, eight hundred sixty-nine thousand, one hundred twenty-eight".