1212111211211 has 4 divisors (see below), whose sum is σ = 1283411870712. Its totient is φ = 1140810551712.

The previous prime is 1212111211151. The next prime is 1212111211219. The reversal of 1212111211211 is 1121121112121.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1212111211211 - 2³⁰ = 1211037469387 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17), and also a Moran number because the ratio is a prime number: 71300659483 = 1212111211211 / (1 + 2 + 1 + 2 + 1 + 1 + 1 + 2 + 1 + 1 + 2 + 1 + 1).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1212111211211.

It is not an unprimeable number, because it can be changed into a prime (1212111211219) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35650329725 + ... + 35650329758.

It is an arithmetic number, because the mean of its divisors is an integer number (320852967678).

Almost surely, 2^{1212111211211} is an apocalyptic number.

1212111211211 is a deficient number, since it is larger than the sum of its proper divisors (71300659501).

1212111211211 is an equidigital number, since it uses as much as digits as its factorization.

1212111211211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71300659500.

The product of its digits is 16, while the sum is 17.

Adding to 1212111211211 its reverse (1121121112121), we get a palindrome (2333232323332).

The spelling of 1212111211211 in words is "one trillion, two hundred twelve billion, one hundred eleven million, two hundred eleven thousand, two hundred eleven".