1165321601 has 4 divisors (see below), whose sum is σ = 1166566212. Its totient is φ = 1164076992.

The previous prime is 1165321523. The next prime is 1165321607. The reversal of 1165321601 is 1061235611.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1061235611 = 23203 ⋅45737.

It can be written as a sum of positive squares in 2 ways, for example, as 76387600 + 1088934001 = 8740^2 + 32999^2 .

It is a cyclic number.

It is not a de Polignac number, because 1165321601 - 2¹⁰ = 1165320577 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1165321607) 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, 620900 + ... + 622773.

It is an arithmetic number, because the mean of its divisors is an integer number (291641553).

Almost surely, 2^1165321601 is an apocalyptic number.

It is an amenable number.

1165321601 is a deficient number, since it is larger than the sum of its proper divisors (1244611).

1165321601 is an equidigital number, since it uses as much as digits as its factorization.

1165321601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1244610.

The product of its (nonzero) digits is 1080, while the sum is 26.

The square root of 1165321601 is about 34136.8071295486. The cubic root of 1165321601 is about 1052.3218764882.

The spelling of 1165321601 in words is "one billion, one hundred sixty-five million, three hundred twenty-one thousand, six hundred one".