21089250 has 192 divisors, whose sum is σ = 70866432. Its totient is φ = 4406400.

The previous prime is 21089213. The next prime is 21089273. The reversal of 21089250 is 5298012.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 204699 + ... + 204801.

It is an arithmetic number, because the mean of its divisors is an integer number (369096).

Almost surely, 2^21089250 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21089250, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35433216).

21089250 is an abundant number, since it is smaller than the sum of its proper divisors (49777182).

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

21089250 is a wasteful number, since it uses less digits than its factorization.

21089250 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146 (or 133 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The square root of 21089250 is about 4592.3033436392. The cubic root of 21089250 is about 276.2827128327.

The spelling of 21089250 in words is "twenty-one million, eighty-nine thousand, two hundred fifty".