1231212121211 has 4 divisors (see below), whose sum is σ = 1231264145232. Its totient is φ = 1231160097192.

The previous prime is 1231212121201. The next prime is 1231212121229. The reversal of 1231212121211 is 1121212121321.

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 1231212121211 - 2¹⁴ = 1231212104827 is a prime.

It is a super-2 number, since 2×1231212121211² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1231212121201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25976495 + ... + 26023848.

It is an arithmetic number, because the mean of its divisors is an integer number (307816036308).

Almost surely, 2^{1231212121211} is an apocalyptic number.

1231212121211 is a deficient number, since it is larger than the sum of its proper divisors (52024021).

1231212121211 is an equidigital number, since it uses as much as digits as its factorization.

1231212121211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52024020.

The product of its digits is 96, while the sum is 20.

Adding to 1231212121211 its reverse (1121212121321), we get a palindrome (2352424242532).

The spelling of 1231212121211 in words is "one trillion, two hundred thirty-one billion, two hundred twelve million, one hundred twenty-one thousand, two hundred eleven".