1165886521 has 2 divisors, whose sum is σ = 1165886522. Its totient is φ = 1165886520.

The previous prime is 1165886509. The next prime is 1165886567. The reversal of 1165886521 is 1256885611.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1165539600 + 346921 = 34140^2 + 589^2 .

It is a cyclic number.

It is not a de Polignac number, because 1165886521 - 2¹⁷ = 1165755449 is a prime.

It is not a weakly prime, because it can be changed into another prime (1165886581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 582943260 + 582943261.

It is an arithmetic number, because the mean of its divisors is an integer number (582943261).

Almost surely, 2^1165886521 is an apocalyptic number.

It is an amenable number.

1165886521 is a deficient number, since it is larger than the sum of its proper divisors (1).

1165886521 is an equidigital number, since it uses as much as digits as its factorization.

1165886521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 115200, while the sum is 43.

The square root of 1165886521 is about 34145.0804802097. The cubic root of 1165886521 is about 1052.4918958308.

The spelling of 1165886521 in words is "one billion, one hundred sixty-five million, eight hundred eighty-six thousand, five hundred twenty-one".