21189276 has 60 divisors (see below), whose sum is σ = 58666608. Its totient is φ = 6645888.

The previous prime is 21189229. The next prime is 21189281. The reversal of 21189276 is 67298112.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 21189276.

It is a congruent number.

It is an unprimeable number.

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 19 ways as a sum of consecutive naturals, for example, 3585 + ... + 7431.

Almost surely, 2^21189276 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21189276, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29333304).

21189276 is an abundant number, since it is smaller than the sum of its proper divisors (37477332).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21189276 is a wasteful number, since it uses less digits than its factorization.

21189276 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3880 (or 3869 counting only the distinct ones).

The product of its digits is 12096, while the sum is 36.

The square root of 21189276 is about 4603.1810739965. The cubic root of 21189276 is about 276.7188256687.

The spelling of 21189276 in words is "twenty-one million, one hundred eighty-nine thousand, two hundred seventy-six".