1211212120 has 16 divisors (see below), whose sum is σ = 2725227360. Its totient is φ = 484484832.

The previous prime is 1211212117. The next prime is 1211212151. The reversal of 1211212120 is 212121121.

It is a self number, because there is not a number n which added to its sum of digits gives 1211212120.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15140112 + ... + 15140191.

It is an arithmetic number, because the mean of its divisors is an integer number (170326710).

Almost surely, 2^1211212120 is an apocalyptic number.

1211212120 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1211212120 is an abundant number, since it is smaller than the sum of its proper divisors (1514015240).

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

1211212120 is a wasteful number, since it uses less digits than its factorization.

1211212120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30280314 (or 30280310 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 13.

The square root of 1211212120 is about 34802.4729006431. The cubic root of 1211212120 is about 1065.9579410980.

Adding to 1211212120 its reverse (212121121), we get a palindrome (1423333241).

Subtracting from 1211212120 its reverse (212121121), we obtain a palindrome (999090999).

The spelling of 1211212120 in words is "one billion, two hundred eleven million, two hundred twelve thousand, one hundred twenty".