1231203313111 has 4 divisors (see below), whose sum is σ = 1273658599800. Its totient is φ = 1188748026424.

The previous prime is 1231203313073. The next prime is 1231203313139. The reversal of 1231203313111 is 1113133021321.

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

It is not a de Polignac number, because 1231203313111 - 2²³ = 1231194924503 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231203313181) 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, 21227643301 + ... + 21227643358.

It is an arithmetic number, because the mean of its divisors is an integer number (318414649950).

Almost surely, 2^{1231203313111} is an apocalyptic number.

1231203313111 is a deficient number, since it is larger than the sum of its proper divisors (42455286689).

1231203313111 is an equidigital number, since it uses as much as digits as its factorization.

1231203313111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42455286688.

The product of its (nonzero) digits is 324, while the sum is 22.

Adding to 1231203313111 its reverse (1113133021321), we get a palindrome (2344336334432).

The spelling of 1231203313111 in words is "one trillion, two hundred thirty-one billion, two hundred three million, three hundred thirteen thousand, one hundred eleven".