1165235261 has 4 divisors (see below), whose sum is σ = 1165336224. Its totient is φ = 1165134300.

The previous prime is 1165235251. The next prime is 1165235297. The reversal of 1165235261 is 1625325611.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 1165235261 - 2²⁶ = 1098126397 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1165235221) 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, 30545 + ... + 57126.

It is an arithmetic number, because the mean of its divisors is an integer number (291334056).

Almost surely, 2^1165235261 is an apocalyptic number.

It is an amenable number.

1165235261 is a deficient number, since it is larger than the sum of its proper divisors (100963).

1165235261 is an equidigital number, since it uses as much as digits as its factorization.

1165235261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100962.

The product of its digits is 10800, while the sum is 32.

The square root of 1165235261 is about 34135.5424887316. The cubic root of 1165235261 is about 1052.2958866056.

The spelling of 1165235261 in words is "one billion, one hundred sixty-five million, two hundred thirty-five thousand, two hundred sixty-one".