1165566131 has 4 divisors (see below), whose sum is σ = 1173285264. Its totient is φ = 1157847000.

The previous prime is 1165566097. The next prime is 1165566203. The reversal of 1165566131 is 1316655611.

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

It is a cyclic number.

It is not a de Polignac number, because 1165566131 - 2²⁶ = 1098457267 is a prime.

It is a super-2 number, since 2×1165566131² = 2717088811468618322, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1165566091 and 1165566100.

It is not an unprimeable number, because it can be changed into a prime (1165566431) 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, 3859340 + ... + 3859641.

It is an arithmetic number, because the mean of its divisors is an integer number (293321316).

Almost surely, 2^1165566131 is an apocalyptic number.

1165566131 is a deficient number, since it is larger than the sum of its proper divisors (7719133).

1165566131 is an equidigital number, since it uses as much as digits as its factorization.

1165566131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7719132.

The product of its digits is 16200, while the sum is 35.

The square root of 1165566131 is about 34140.3885595932. The cubic root of 1165566131 is about 1052.3954774213.

The spelling of 1165566131 in words is "one billion, one hundred sixty-five million, five hundred sixty-six thousand, one hundred thirty-one".