1205541613 has 4 divisors (see below), whose sum is σ = 1213220380. Its totient is φ = 1197862848.

The previous prime is 1205541599. The next prime is 1205541647. The reversal of 1205541613 is 3161455021.

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 833938884 + 371602729 = 28878^2 + 19277^2 .

It is a cyclic number.

It is not a de Polignac number, because 1205541613 - 2⁵ = 1205541581 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 (1205541413) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3839148 + ... + 3839461.

It is an arithmetic number, because the mean of its divisors is an integer number (303305095).

Almost surely, 2^1205541613 is an apocalyptic number.

It is an amenable number.

1205541613 is a deficient number, since it is larger than the sum of its proper divisors (7678767).

1205541613 is an equidigital number, since it uses as much as digits as its factorization.

1205541613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7678766.

The product of its (nonzero) digits is 3600, while the sum is 28.

The square root of 1205541613 is about 34720.9103135272. The cubic root of 1205541613 is about 1064.2918471865.

Adding to 1205541613 its reverse (3161455021), we get a palindrome (4366996634).

The spelling of 1205541613 in words is "one billion, two hundred five million, five hundred forty-one thousand, six hundred thirteen".