1165175981 has 2 divisors, whose sum is σ = 1165175982. Its totient is φ = 1165175980.

The previous prime is 1165175941. The next prime is 1165175983. The reversal of 1165175981 is 1895715611.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 884110756 + 281065225 = 29734^2 + 16765^2 .

It is a cyclic number.

It is not a de Polignac number, because 1165175981 - 2³⁰ = 91434157 is a prime.

It is a super-2 number, since 2×1165175981² = 2715270133398624722, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 1165175983, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1165175983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 582587990 + 582587991.

It is an arithmetic number, because the mean of its divisors is an integer number (582587991).

Almost surely, 2^1165175981 is an apocalyptic number.

It is an amenable number.

1165175981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1165175981 is an equidigital number, since it uses as much as digits as its factorization.

1165175981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 75600, while the sum is 44.

The square root of 1165175981 is about 34134.6741745106. The cubic root of 1165175981 is about 1052.2780415231.

The spelling of 1165175981 in words is "one billion, one hundred sixty-five million, one hundred seventy-five thousand, nine hundred eighty-one".