1231111142 has 4 divisors (see below), whose sum is σ = 1846666716. Its totient is φ = 615555570.

The previous prime is 1231111129. The next prime is 1231111171. The reversal of 1231111142 is 2411111321.

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

It is a self number, because there is not a number n which added to its sum of digits gives 1231111142.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 307777784 + ... + 307777787.

It is an arithmetic number, because the mean of its divisors is an integer number (461666679).

Almost surely, 2^1231111142 is an apocalyptic number.

1231111142 is a deficient number, since it is larger than the sum of its proper divisors (615555574).

1231111142 is an equidigital number, since it uses as much as digits as its factorization.

1231111142 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 615555573.

The product of its digits is 48, while the sum is 17.

The square root of 1231111142 is about 35087.1934186820. The cubic root of 1231111142 is about 1071.7638076533.

Adding to 1231111142 its reverse (2411111321), we get a palindrome (3642222463).

The spelling of 1231111142 in words is "one billion, two hundred thirty-one million, one hundred eleven thousand, one hundred forty-two".