21440800 has 36 divisors (see below), whose sum is σ = 52344306. Its totient is φ = 8576000.

The previous prime is 21440719. The next prime is 21440801. The reversal of 21440800 is 804412.

It can be written as a sum of positive squares in 3 ways, for example, as 14107536 + 7333264 = 3756^2 + 2708^2 .

It is not an unprimeable number, because it can be changed into a prime (21440801) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12601 + ... + 14200.

Almost surely, 2^21440800 is an apocalyptic number.

21440800 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21440800 is an abundant number, since it is smaller than the sum of its proper divisors (30903506).

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

21440800 is a wasteful number, since it uses less digits than its factorization.

21440800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26821 (or 26808 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 19.

The square root of 21440800 is about 4630.4211471528. The cubic root of 21440800 is about 277.8094375766.

It can be divided in two parts, 214 and 40800, that added together give a palindrome (41014).

The spelling of 21440800 in words is "twenty-one million, four hundred forty thousand, eight hundred".