1221231231 has 12 divisors (see below), whose sum is σ = 1924364520. Its totient is φ = 740140080.

The previous prime is 1221231203. The next prime is 1221231233. The reversal of 1221231231 is 1321321221.

It is not a de Polignac number, because 1221231231 - 2¹³ = 1221223039 is a prime.

It is a super-2 number, since 2×1221231231² = 2982811439139550722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221231233) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6167736 + ... + 6167933.

It is an arithmetic number, because the mean of its divisors is an integer number (160363710).

Almost surely, 2^1221231231 is an apocalyptic number.

1221231231 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1221231231 is a deficient number, since it is larger than the sum of its proper divisors (703133289).

1221231231 is a wasteful number, since it uses less digits than its factorization.

1221231231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12335686 (or 12335683 counting only the distinct ones).

The product of its digits is 144, while the sum is 18.

The square root of 1221231231 is about 34946.1189690644. The cubic root of 1221231231 is about 1068.8890647400.

Adding to 1221231231 its reverse (1321321221), we get a palindrome (2542552452).

The spelling of 1221231231 in words is "one billion, two hundred twenty-one million, two hundred thirty-one thousand, two hundred thirty-one".