1231115405 has 16 divisors (see below), whose sum is σ = 1629787824. Its totient is φ = 886955520.

The previous prime is 1231115383. The next prime is 1231115407. The reversal of 1231115405 is 5045111321.

It can be written as a sum of positive squares in 8 ways, for example, as 277355716 + 953759689 = 16654^2 + 30883^2 .

It is not a de Polignac number, because 1231115405 - 2⁶ = 1231115341 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 (1231115407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 228314 + ... + 233643.

It is an arithmetic number, because the mean of its divisors is an integer number (101861739).

Almost surely, 2^1231115405 is an apocalyptic number.

It is an amenable number.

1231115405 is a deficient number, since it is larger than the sum of its proper divisors (398672419).

1231115405 is a wasteful number, since it uses less digits than its factorization.

1231115405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 462016.

The product of its (nonzero) digits is 600, while the sum is 23.

The square root of 1231115405 is about 35087.2541672899. The cubic root of 1231115405 is about 1071.7650447265.

Adding to 1231115405 its reverse (5045111321), we get a palindrome (6276226726).

The spelling of 1231115405 in words is "one billion, two hundred thirty-one million, one hundred fifteen thousand, four hundred five".