21980800 has 48 divisors (see below), whose sum is σ = 54307350. Its totient is φ = 8791040.

The previous prime is 21980789. The next prime is 21980809. The reversal of 21980800 is 808912.

It can be written as a sum of positive squares in 3 ways, for example, as 9193024 + 12787776 = 3032^2 + 3576^2 .

It is not an unprimeable number, because it can be changed into a prime (21980809) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 235 + ... + 6634.

Almost surely, 2^21980800 is an apocalyptic number.

21980800 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 21980800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27153675).

21980800 is an abundant number, since it is smaller than the sum of its proper divisors (32326550).

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

21980800 is an equidigital number, since it uses as much as digits as its factorization.

21980800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6893 (or 6876 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 28.

The square root of 21980800 is about 4688.3685861929. The cubic root of 21980800 is about 280.1223954695.

The spelling of 21980800 in words is "twenty-one million, nine hundred eighty thousand, eight hundred".