21205181200 has 360 divisors, whose sum is σ = 65501021952. Its totient is φ = 6542807040.

The previous prime is 21205181197. The next prime is 21205181201. The reversal of 21205181200 is 218150212.

It is not an unprimeable number, because it can be changed into a prime (21205181201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 7662217 + ... + 7664983.

Almost surely, 2^21205181200 is an apocalyptic number.

21205181200 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 21205181200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32750510976).

21205181200 is an abundant number, since it is smaller than the sum of its proper divisors (44295840752).

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

21205181200 is a wasteful number, since it uses less digits than its factorization.

21205181200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2839 (or 2821 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 22.

The spelling of 21205181200 in words is "twenty-one billion, two hundred five million, one hundred eighty-one thousand, two hundred".