1231055405 has 4 divisors (see below), whose sum is σ = 1477266492. Its totient is φ = 984844320.

The previous prime is 1231055401. The next prime is 1231055461. The reversal of 1231055405 is 5045501321.

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

It can be written as a sum of positive squares in 2 ways, for example, as 981067684 + 249987721 = 31322^2 + 15811^2 .

It is not a de Polignac number, because 1231055405 - 2² = 1231055401 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 (1231055401) 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 3 ways as a sum of consecutive naturals, for example, 123105536 + ... + 123105545.

It is an arithmetic number, because the mean of its divisors is an integer number (369316623).

Almost surely, 2^1231055405 is an apocalyptic number.

It is an amenable number.

1231055405 is a deficient number, since it is larger than the sum of its proper divisors (246211087).

1231055405 is an equidigital number, since it uses as much as digits as its factorization.

1231055405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 246211086.

The product of its (nonzero) digits is 3000, while the sum is 26.

The square root of 1231055405 is about 35086.3991455379. The cubic root of 1231055405 is about 1071.7476331589.

Adding to 1231055405 its reverse (5045501321), we get a palindrome (6276556726).

The spelling of 1231055405 in words is "one billion, two hundred thirty-one million, fifty-five thousand, four hundred five".