21012201200 has 60 divisors (see below), whose sum is σ = 50566666800. Its totient is φ = 8390753280.

The previous prime is 21012201113. The next prime is 21012201211. The reversal of 21012201200 is 210221012.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 195752 + ... + 283448.

It is an arithmetic number, because the mean of its divisors is an integer number (842777780).

Almost surely, 2^21012201200 is an apocalyptic number.

21012201200 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 21012201200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25283333400).

21012201200 is an abundant number, since it is smaller than the sum of its proper divisors (29554465600).

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

21012201200 is a wasteful number, since it uses less digits than its factorization.

21012201200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88314 (or 88303 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 21012201200 its reverse (210221012), we get a palindrome (21222422212).

The spelling of 21012201200 in words is "twenty-one billion, twelve million, two hundred one thousand, two hundred".