21185000 has 80 divisors (see below), whose sum is σ = 52483200. Its totient is φ = 7992000.

The previous prime is 21184967. The next prime is 21185011. The reversal of 21185000 is 58112.

It is a self number, because there is not a number n which added to its sum of digits gives 21185000.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 94889 + ... + 95111.

It is an arithmetic number, because the mean of its divisors is an integer number (656040).

Almost surely, 2^21185000 is an apocalyptic number.

21185000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21185000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26241600).

21185000 is an abundant number, since it is smaller than the sum of its proper divisors (31298200).

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

21185000 is a wasteful number, since it uses less digits than its factorization.

21185000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 268 (or 249 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 17.

The square root of 21185000 is about 4602.7165891460. The cubic root of 21185000 is about 276.7002104456.

The spelling of 21185000 in words is "twenty-one million, one hundred eighty-five thousand".