121000021200 has 180 divisors, whose sum is σ = 424622827980. Its totient is φ = 31904040960.

The previous prime is 121000021199. The next prime is 121000021213. The reversal of 121000021200 is 2120000121.

It can be written as a sum of positive squares in 6 ways, for example, as 20074355856 + 100925665344 = 141684^2 + 317688^2 .

It is a tau number, because it is divible by the number of its divisors (180).

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 131574 + ... + 509226.

It is an arithmetic number, because the mean of its divisors is an integer number (2359015711).

Almost surely, 2^121000021200 is an apocalyptic number.

121000021200 is a gapful number since it is divisible by the number (10) 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 121000021200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (212311413990).

121000021200 is an abundant number, since it is smaller than the sum of its proper divisors (303622806780).

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

121000021200 is a wasteful number, since it uses less digits than its factorization.

121000021200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 377766 (or 377752 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 121000021200 its reverse (2120000121), we get a palindrome (123120021321).

The spelling of 121000021200 in words is "one hundred twenty-one billion, twenty-one thousand, two hundred".