21986800 has 120 divisors (see below), whose sum is σ = 60888960. Its totient is φ = 7545600.

The previous prime is 21986777. The next prime is 21986807. The reversal of 21986800 is 868912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21986807) 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, 83469 + ... + 83731.

It is an arithmetic number, because the mean of its divisors is an integer number (507408).

Almost surely, 2^21986800 is an apocalyptic number.

21986800 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 21986800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30444480).

21986800 is an abundant number, since it is smaller than the sum of its proper divisors (38902160).

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

21986800 is a wasteful number, since it uses less digits than its factorization.

21986800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 311 (or 300 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 34.

The square root of 21986800 is about 4689.0084239634. The cubic root of 21986800 is about 280.1478810670.

It can be divided in two parts, 2198 and 6800, that added together give a palindrome (8998).

The spelling of 21986800 in words is "twenty-one million, nine hundred eighty-six thousand, eight hundred".