121221000000100 has 576 divisors, whose sum is σ = 363138101673984. Its totient is φ = 33900249600000.

The previous prime is 121221000000073. The next prime is 121221000000151. The reversal of 121221000000100 is 1000000122121.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 1112156605 + ... + 1112265595.

It is an arithmetic number, because the mean of its divisors is an integer number (630448093184).

Almost surely, 2^{121221000000100} is an apocalyptic number.

121221000000100 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 121221000000100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (181569050836992).

121221000000100 is an abundant number, since it is smaller than the sum of its proper divisors (241917101673884).

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

121221000000100 is a wasteful number, since it uses less digits than its factorization.

121221000000100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109348 (or 109341 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 121221000000100 its reverse (1000000122121), we get a palindrome (122221000122221).

The spelling of 121221000000100 in words is "one hundred twenty-one trillion, two hundred twenty-one billion, one hundred", and thus it is an aban number.