20121021200 has 120 divisors (see below), whose sum is σ = 57028968960. Its totient is φ = 6676070400.

The previous prime is 20121021199. The next prime is 20121021233. The reversal of 20121021200 is 212012102.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 29105 + ... + 202704.

It is an arithmetic number, because the mean of its divisors is an integer number (475241408).

Almost surely, 2^20121021200 is an apocalyptic number.

20121021200 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 20121021200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28514484480).

20121021200 is an abundant number, since it is smaller than the sum of its proper divisors (36907947760).

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

20121021200 is a wasteful number, since it uses less digits than its factorization.

20121021200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 231865 (or 231854 counting only the distinct ones).

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

Adding to 20121021200 its reverse (212012102), we get a palindrome (20333033302).

The spelling of 20121021200 in words is "twenty billion, one hundred twenty-one million, twenty-one thousand, two hundred".