1231111201 has 4 divisors (see below), whose sum is σ = 1247975812. Its totient is φ = 1214246592.

The previous prime is 1231111177. The next prime is 1231111307. The reversal of 1231111201 is 1021111321.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1021111321 = 383 ⋅2666087.

It can be written as a sum of positive squares in 2 ways, for example, as 605110801 + 626000400 = 24599^2 + 25020^2 .

It is a cyclic number.

It is not a de Polignac number, because 1231111201 - 2⁹ = 1231110689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1231111601) 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, 8432196 + ... + 8432341.

It is an arithmetic number, because the mean of its divisors is an integer number (311993953).

Almost surely, 2^1231111201 is an apocalyptic number.

It is an amenable number.

1231111201 is a deficient number, since it is larger than the sum of its proper divisors (16864611).

1231111201 is an equidigital number, since it uses as much as digits as its factorization.

1231111201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16864610.

The product of its (nonzero) digits is 12, while the sum is 13.

The square root of 1231111201 is about 35087.1942594446. The cubic root of 1231111201 is about 1071.7638247744.

Adding to 1231111201 its reverse (1021111321), we get a palindrome (2252222522).

The spelling of 1231111201 in words is "one billion, two hundred thirty-one million, one hundred eleven thousand, two hundred one".