1165332561 has 8 divisors (see below), whose sum is σ = 1556338944. Its totient is φ = 775607280.

The previous prime is 1165332547. The next prime is 1165332577. The reversal of 1165332561 is 1652335611.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1165332561 - 2¹⁹ = 1164808273 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1165330561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 318150 + ... + 321791.

It is an arithmetic number, because the mean of its divisors is an integer number (194542368).

Almost surely, 2^1165332561 is an apocalyptic number.

It is an amenable number.

1165332561 is a deficient number, since it is larger than the sum of its proper divisors (391006383).

1165332561 is an equidigital number, since it uses as much as digits as its factorization.

1165332561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 640551.

The product of its digits is 16200, while the sum is 33.

The square root of 1165332561 is about 34136.9676597087. The cubic root of 1165332561 is about 1052.3251755522.

The spelling of 1165332561 in words is "one billion, one hundred sixty-five million, three hundred thirty-two thousand, five hundred sixty-one".