121210021100 has 432 divisors, whose sum is σ = 329153932800. Its totient is φ = 38557370880.

The previous prime is 121210021099. The next prime is 121210021103. The reversal of 121210021100 is 1120012121.

It is not an unprimeable number, because it can be changed into a prime (121210021103) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 507154781 + ... + 507155019.

It is an arithmetic number, because the mean of its divisors is an integer number (761930400).

Almost surely, 2^121210021100 is an apocalyptic number.

121210021100 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 121210021100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (164576966400).

121210021100 is an abundant number, since it is smaller than the sum of its proper divisors (207943911700).

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

121210021100 is a wasteful number, since it uses less digits than its factorization.

121210021100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 422 (or 408 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 121210021100 its reverse (1120012121), we get a palindrome (122330033221).

The spelling of 121210021100 in words is "one hundred twenty-one billion, two hundred ten million, twenty-one thousand, one hundred".