21998800 has 60 divisors (see below), whose sum is σ = 54123520. Its totient is φ = 8588160.

The previous prime is 21998777. The next prime is 21998803. The reversal of 21998800 is 889912.

It is a self number, because there is not a number n which added to its sum of digits gives 21998800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21998803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16561 + ... + 17839.

Almost surely, 2^21998800 is an apocalyptic number.

21998800 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 21998800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27061760).

21998800 is an abundant number, since it is smaller than the sum of its proper divisors (32124720).

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

21998800 is a wasteful number, since it uses less digits than its factorization.

21998800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1340 (or 1329 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 37.

The square root of 21998800 is about 4690.2878376492. The cubic root of 21998800 is about 280.1988383559.

The spelling of 21998800 in words is "twenty-one million, nine hundred ninety-eight thousand, eight hundred".