21052800 has 288 divisors, whose sum is σ = 81389880. Its totient is φ = 5160960.

The previous prime is 21052771. The next prime is 21052841. The reversal of 21052800 is 825012.

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 489579 + ... + 489621.

Almost surely, 2^21052800 is an apocalyptic number.

21052800 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 21052800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40694940).

21052800 is an abundant number, since it is smaller than the sum of its proper divisors (60337080).

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

21052800 is a wasteful number, since it uses less digits than its factorization.

21052800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90 (or 70 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

The square root of 21052800 is about 4588.3330306332. Note that the first 3 decimals coincide. The cubic root of 21052800 is about 276.1234482420.

Adding to 21052800 its reverse (825012), we get a palindrome (21877812).

The spelling of 21052800 in words is "twenty-one million, fifty-two thousand, eight hundred".