121221210000 has 400 divisors, whose sum is σ = 431237809728. Its totient is φ = 29088000000.

The previous prime is 121221209999. The next prime is 121221210017. The reversal of 121221210000 is 12122121.

It is a tau number, because it is divible by the number of its divisors (400).

It is a Harshad number since it is a multiple of its sum of digits (12).

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 79 ways as a sum of consecutive naturals, for example, 33328182 + ... + 33331818.

Almost surely, 2^121221210000 is an apocalyptic number.

121221210000 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 121221210000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (215618904864).

121221210000 is an abundant number, since it is smaller than the sum of its proper divisors (310016599728).

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

121221210000 is a wasteful number, since it uses less digits than its factorization.

121221210000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3780 (or 3759 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 121221210000 its reverse (12122121), we get a palindrome (121233332121).

121221210000 divided by its reverse (12122121) gives a 4-th power (10000 = 10⁴).

It can be divided in two parts, 1212 and 21210000, that added together give a palindrome (21211212).

The spelling of 121221210000 in words is "one hundred twenty-one billion, two hundred twenty-one million, two hundred ten thousand".