1211211212120 has 128 divisors (see below), whose sum is σ = 3551424912000. Its totient is φ = 360779636736.

The previous prime is 1211211212063. The next prime is 1211211212129. The reversal of 1211211212120 is 212121121121.

It is a super-3 number, since 3×1211211212120³ (a number of 37 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211211212129) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9724895 + ... + 9848654.

It is an arithmetic number, because the mean of its divisors is an integer number (27745507125).

Almost surely, 2^{1211211212120} is an apocalyptic number.

1211211212120 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1211211212120 is an abundant number, since it is smaller than the sum of its proper divisors (2340213699880).

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

1211211212120 is a wasteful number, since it uses less digits than its factorization.

1211211212120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19573597 (or 19573593 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 1211211212120 its reverse (212121121121), we get a palindrome (1423332333241).

Subtracting from 1211211212120 its reverse (212121121121), we obtain a palindrome (999090090999).

The spelling of 1211211212120 in words is "one trillion, two hundred eleven billion, two hundred eleven million, two hundred twelve thousand, one hundred twenty".