21140800 has 84 divisors (see below), whose sum is σ = 53023516. Its totient is φ = 8294400.

The previous prime is 21140783. The next prime is 21140807. The reversal of 21140800 is 804112.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 3968064 + 17172736 = 1992^2 + 4144^2 .

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a zygodrome in base 4.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21140807) 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, 116710 + ... + 116890.

Almost surely, 2^21140800 is an apocalyptic number.

21140800 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 21140800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26511758).

21140800 is an abundant number, since it is smaller than the sum of its proper divisors (31882716).

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

21140800 is a wasteful number, since it uses less digits than its factorization.

21140800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 276 (or 261 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

The square root of 21140800 is about 4597.9125698517. The cubic root of 21140800 is about 276.5076423587.

Adding to 21140800 its reverse (804112), we get a palindrome (21944912).

The spelling of 21140800 in words is "twenty-one million, one hundred forty thousand, eight hundred".