21244200 has 48 divisors (see below), whose sum is σ = 65858880. Its totient is φ = 5664960.

The previous prime is 21244199. The next prime is 21244213. The reversal of 21244200 is 244212.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21244200.

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, 17104 + ... + 18303.

It is an arithmetic number, because the mean of its divisors is an integer number (1372060).

Almost surely, 2^21244200 is an apocalyptic number.

21244200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21244200 is an abundant number, since it is smaller than the sum of its proper divisors (44614680).

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

21244200 is a wasteful number, since it uses less digits than its factorization.

21244200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35426 (or 35417 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 15.

The square root of 21244200 is about 4609.1430873862. The cubic root of 21244200 is about 276.9577105306.

Adding to 21244200 its reverse (244212), we get a palindrome (21488412).

The spelling of 21244200 in words is "twenty-one million, two hundred forty-four thousand, two hundred".