21000200 has 96 divisors (see below), whose sum is σ = 54137160. Its totient is φ = 7526400.

The previous prime is 21000193. The next prime is 21000229. The reversal of 21000200 is 200012.

21000200 is an esthetic number in base 9, because in such base its adjacent digits differ by 1.

It can be written as a sum of positive squares in 12 ways, for example, as 188356 + 20811844 = 434^2 + 4562^2 .

It is a Harshad number since it is a multiple of its sum of digits (5).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 106502 + ... + 106698.

Almost surely, 2^21000200 is an apocalyptic number.

21000200 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 21000200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27068580).

21000200 is an abundant number, since it is smaller than the sum of its proper divisors (33136960).

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

21000200 is a wasteful number, since it uses less digits than its factorization.

21000200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 267 (or 258 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 5.

The square root of 21000200 is about 4582.5975166929. The cubic root of 21000200 is about 275.8932934843.

Adding to 21000200 its reverse (200012), we get a palindrome (21200212).

The spelling of 21000200 in words is "twenty-one million, two hundred", and thus it is an aban number.