1131661523 has 4 divisors (see below), whose sum is σ = 1132199208. Its totient is φ = 1131123840.

The previous prime is 1131661507. The next prime is 1131661529. The reversal of 1131661523 is 3251661311.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3251661311 = 19 ⋅171140069.

It is a cyclic number.

It is not a de Polignac number, because 1131661523 - 2⁴ = 1131661507 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1131661529) 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, 265673 + ... + 269898.

It is an arithmetic number, because the mean of its divisors is an integer number (283049802).

Almost surely, 2^1131661523 is an apocalyptic number.

1131661523 is a deficient number, since it is larger than the sum of its proper divisors (537685).

1131661523 is an equidigital number, since it uses as much as digits as its factorization.

1131661523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 537684.

The product of its digits is 3240, while the sum is 29.

The square root of 1131661523 is about 33640.1772141587. The cubic root of 1131661523 is about 1042.0906916813.

The spelling of 1131661523 in words is "one billion, one hundred thirty-one million, six hundred sixty-one thousand, five hundred twenty-three".