21054800 has 60 divisors (see below), whose sum is σ = 54488700. Its totient is φ = 7772160.

The previous prime is 21054791. The next prime is 21054811. The reversal of 21054800 is 845012.

It can be written as a sum of positive squares in 6 ways, for example, as 4343056 + 16711744 = 2084^2 + 4088^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3176 + ... + 7224.

It is an arithmetic number, because the mean of its divisors is an integer number (908145).

Almost surely, 2^21054800 is an apocalyptic number.

21054800 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 21054800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27244350).

21054800 is an abundant number, since it is smaller than the sum of its proper divisors (33433900).

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

21054800 is a wasteful number, since it uses less digits than its factorization.

21054800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4080 (or 4069 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 20.

The square root of 21054800 is about 4588.5509695328. The cubic root of 21054800 is about 276.1321918043.

Adding to 21054800 its reverse (845012), we get a palindrome (21899812).

The spelling of 21054800 in words is "twenty-one million, fifty-four thousand, eight hundred".