21084798 has 48 divisors (see below), whose sum is σ = 50766480. Its totient is φ = 5814144.

The previous prime is 21084797. The next prime is 21084803. The reversal of 21084798 is 89748012.

It is a hoax number, since the sum of its digits (39) coincides with the sum of the digits of its distinct prime factors.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21084797) 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, 7290 + ... + 9762.

It is an arithmetic number, because the mean of its divisors is an integer number (1057635).

Almost surely, 2^21084798 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21084798, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25383240).

21084798 is an abundant number, since it is smaller than the sum of its proper divisors (29681682).

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

21084798 is a wasteful number, since it uses less digits than its factorization.

21084798 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2521 (or 2514 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 39.

The square root of 21084798 is about 4591.8185939778. The cubic root of 21084798 is about 276.2632701118.

The spelling of 21084798 in words is "twenty-one million, eighty-four thousand, seven hundred ninety-eight".