1211333231 has 4 divisors (see below), whose sum is σ = 1211811000. Its totient is φ = 1210855464.

The previous prime is 1211333213. The next prime is 1211333237. The reversal of 1211333231 is 1323331121.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1211333231 is a prime.

It is a super-2 number, since 2×1211333231² = 2934656393049798722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211333237) 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 3 ways as a sum of consecutive naturals, for example, 235061 + ... + 240158.

It is an arithmetic number, because the mean of its divisors is an integer number (302952750).

Almost surely, 2^1211333231 is an apocalyptic number.

1211333231 is a deficient number, since it is larger than the sum of its proper divisors (477769).

1211333231 is an equidigital number, since it uses as much as digits as its factorization.

1211333231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 477768.

The product of its digits is 324, while the sum is 20.

The square root of 1211333231 is about 34804.2128340809. The cubic root of 1211333231 is about 1065.9934688494.

Adding to 1211333231 its reverse (1323331121), we get a palindrome (2534664352).

The spelling of 1211333231 in words is "one billion, two hundred eleven million, three hundred thirty-three thousand, two hundred thirty-one".