1221123231 has 12 divisors (see below), whose sum is σ = 1764212008. Its totient is φ = 813912624.

The previous prime is 1221123221. The next prime is 1221123257. The reversal of 1221123231 is 1323211221.

It is not a de Polignac number, because 1221123231 - 2¹⁰ = 1221122207 is a prime.

It is a super-2 number, since 2×1221123231² = 2982283890575758722, 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 (1221123221) 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, 44136 + ... + 66258.

Almost surely, 2^1221123231 is an apocalyptic number.

1221123231 is a deficient number, since it is larger than the sum of its proper divisors (543088777).

1221123231 is a wasteful number, since it uses less digits than its factorization.

1221123231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28262 (or 28259 counting only the distinct ones).

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

The square root of 1221123231 is about 34944.5736989307. The cubic root of 1221123231 is about 1068.8575546216.

Adding to 1221123231 its reverse (1323211221), we get a palindrome (2544334452).

The spelling of 1221123231 in words is "one billion, two hundred twenty-one million, one hundred twenty-three thousand, two hundred thirty-one".