21804894 has 48 divisors (see below), whose sum is σ = 50294400. Its totient is φ = 6807888.

The previous prime is 21804857. The next prime is 21804901. The reversal of 21804894 is 49840812.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 34917 + ... + 35535.

It is an arithmetic number, because the mean of its divisors is an integer number (1047800).

Almost surely, 2^21804894 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21804894, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25147200).

21804894 is an abundant number, since it is smaller than the sum of its proper divisors (28489506).

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

21804894 is a wasteful number, since it uses less digits than its factorization.

21804894 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 749 (or 746 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The square root of 21804894 is about 4669.5710723791. The cubic root of 21804894 is about 279.3731469931.

The spelling of 21804894 in words is "twenty-one million, eight hundred four thousand, eight hundred ninety-four".