1231345211 has 4 divisors (see below), whose sum is σ = 1237725432. Its totient is φ = 1224964992.

The previous prime is 1231345201. The next prime is 1231345231. The reversal of 1231345211 is 1125431321.

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 1231345211 - 2⁶ = 1231345147 is a prime.

It is a super-2 number, since 2×1231345211² = 3032422057305269042, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1231345201) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3189821 + ... + 3190206.

It is an arithmetic number, because the mean of its divisors is an integer number (309431358).

Almost surely, 2^1231345211 is an apocalyptic number.

1231345211 is a deficient number, since it is larger than the sum of its proper divisors (6380221).

1231345211 is an equidigital number, since it uses as much as digits as its factorization.

1231345211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6380220.

The product of its digits is 720, while the sum is 23.

The square root of 1231345211 is about 35090.5287933938. The cubic root of 1231345211 is about 1071.8317275393.

Adding to 1231345211 its reverse (1125431321), we get a palindrome (2356776532).

The spelling of 1231345211 in words is "one billion, two hundred thirty-one million, three hundred forty-five thousand, two hundred eleven".