1131205613 has 4 divisors (see below), whose sum is σ = 1132938588. Its totient is φ = 1129472640.

The previous prime is 1131205609. The next prime is 1131205631. The reversal of 1131205613 is 3165021311.

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 305620324 + 825585289 = 17482^2 + 28733^2 .

It is a cyclic number.

It is not a de Polignac number, because 1131205613 - 2² = 1131205609 is a prime.

It is a super-2 number, since 2×1131205613² = 2559252277765411538, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1131205013) 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, 865508 + ... + 866813.

It is an arithmetic number, because the mean of its divisors is an integer number (283234647).

Almost surely, 2^1131205613 is an apocalyptic number.

It is an amenable number.

1131205613 is a deficient number, since it is larger than the sum of its proper divisors (1732975).

1131205613 is an equidigital number, since it uses as much as digits as its factorization.

1131205613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1732974.

The product of its (nonzero) digits is 540, while the sum is 23.

The square root of 1131205613 is about 33633.4002592661. The cubic root of 1131205613 is about 1041.9507312860.

Adding to 1131205613 its reverse (3165021311), we get a palindrome (4296226924).

The spelling of 1131205613 in words is "one billion, one hundred thirty-one million, two hundred five thousand, six hundred thirteen".