21089850 has 48 divisors (see below), whose sum is σ = 54585792. Its totient is φ = 5378560.

The previous prime is 21089839. The next prime is 21089851. The reversal of 21089850 is 5898012.

It is a happy number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21089851) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 394 + ... + 6506.

It is an arithmetic number, because the mean of its divisors is an integer number (1137204).

Almost surely, 2^21089850 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21089850, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27292896).

21089850 is an abundant number, since it is smaller than the sum of its proper divisors (33495942).

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

21089850 is a wasteful number, since it uses less digits than its factorization.

21089850 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6151 (or 6146 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 33.

The square root of 21089850 is about 4592.3686698696. The cubic root of 21089850 is about 276.2853329362.

The spelling of 21089850 in words is "twenty-one million, eighty-nine thousand, eight hundred fifty".