121555240212 has 72 divisors (see below), whose sum is σ = 344280718656. Its totient is φ = 33220061952.

The previous prime is 121555240181. The next prime is 121555240271. The reversal of 121555240212 is 212042555121.

It is a self number, because there is not a number n which added to its sum of digits gives 121555240212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4480533 + ... + 4507580.

It is an arithmetic number, because the mean of its divisors is an integer number (4781676648).

Almost surely, 2^121555240212 is an apocalyptic number.

121555240212 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

121555240212 is an abundant number, since it is smaller than the sum of its proper divisors (222725478444).

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

121555240212 is a wasteful number, since it uses less digits than its factorization.

121555240212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8988157 (or 8988148 counting only the distinct ones).

The product of its (nonzero) digits is 8000, while the sum is 30.

Adding to 121555240212 its reverse (212042555121), we get a palindrome (333597795333).

The spelling of 121555240212 in words is "one hundred twenty-one billion, five hundred fifty-five million, two hundred forty thousand, two hundred twelve".