1231221211 has 16 divisors (see below), whose sum is σ = 1404910080. Its totient is φ = 1068059520.

The previous prime is 1231221191. The next prime is 1231221239. The reversal of 1231221211 is 1121221321.

It is not a de Polignac number, because 1231221211 - 2⁵ = 1231221179 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1231221811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 103930 + ... + 115168.

It is an arithmetic number, because the mean of its divisors is an integer number (87806880).

Almost surely, 2^1231221211 is an apocalyptic number.

1231221211 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1231221211 is a deficient number, since it is larger than the sum of its proper divisors (173688869).

1231221211 is a wasteful number, since it uses less digits than its factorization.

1231221211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11706.

The product of its digits is 48, while the sum is 16.

The square root of 1231221211 is about 35088.7618903831. The cubic root of 1231221211 is about 1071.7957474869.

Adding to 1231221211 its reverse (1121221321), we get a palindrome (2352442532).

The spelling of 1231221211 in words is "one billion, two hundred thirty-one million, two hundred twenty-one thousand, two hundred eleven".