21982400 has 84 divisors (see below), whose sum is σ = 59055000. Its totient is φ = 7987200.

The previous prime is 21982393. The next prime is 21982409. The reversal of 21982400 is 428912.

It is a self number, because there is not a number n which added to its sum of digits gives 21982400.

It is not an unprimeable number, because it can be changed into a prime (21982409) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16976 + ... + 18224.

Almost surely, 2^21982400 is an apocalyptic number.

21982400 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 21982400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29527500).

21982400 is an abundant number, since it is smaller than the sum of its proper divisors (37072600).

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

21982400 is a wasteful number, since it uses less digits than its factorization.

21982400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1282 (or 1267 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 21982400 is about 4688.5392181361. The cubic root of 21982400 is about 280.1291920822.

The spelling of 21982400 in words is "twenty-one million, nine hundred eighty-two thousand, four hundred".