1165280321 has 2 divisors, whose sum is σ = 1165280322. Its totient is φ = 1165280320.

The previous prime is 1165280309. The next prime is 1165280323. The reversal of 1165280321 is 1230825611.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1158721600 + 6558721 = 34040^2 + 2561^2 .

It is a cyclic number.

It is not a de Polignac number, because 1165280321 - 2¹⁴ = 1165263937 is a prime.

It is a Sophie Germain prime.

Together with 1165280323, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1165280323) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 582640160 + 582640161.

It is an arithmetic number, because the mean of its divisors is an integer number (582640161).

Almost surely, 2^1165280321 is an apocalyptic number.

It is an amenable number.

1165280321 is a deficient number, since it is larger than the sum of its proper divisors (1).

1165280321 is an equidigital number, since it uses as much as digits as its factorization.

1165280321 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 1165280321 is about 34136.2024982276. The cubic root of 1165280321 is about 1052.3094506308.

The spelling of 1165280321 in words is "one billion, one hundred sixty-five million, two hundred eighty thousand, three hundred twenty-one".