11131153661 has 4 divisors (see below), whose sum is σ = 11283635292. Its totient is φ = 10978672032.

The previous prime is 11131153619. The next prime is 11131153681. The reversal of 11131153661 is 16635113111.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16635113111 = 19 ⋅875532269.

It can be written as a sum of positive squares in 2 ways, for example, as 7496269561 + 3634884100 = 86581^2 + 60290^2 .

It is a cyclic number.

It is not a de Polignac number, because 11131153661 - 2¹⁸ = 11130891517 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 (11131153681) 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, 76240706 + ... + 76240851.

It is an arithmetic number, because the mean of its divisors is an integer number (2820908823).

Almost surely, 2^11131153661 is an apocalyptic number.

It is an amenable number.

11131153661 is a deficient number, since it is larger than the sum of its proper divisors (152481631).

11131153661 is an equidigital number, since it uses as much as digits as its factorization.

11131153661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152481630.

The product of its digits is 1620, while the sum is 29.

Adding to 11131153661 its reverse (16635113111), we get a palindrome (27766266772).

The spelling of 11131153661 in words is "eleven billion, one hundred thirty-one million, one hundred fifty-three thousand, six hundred sixty-one".