1165323280 has 80 divisors (see below), whose sum is σ = 2989094400. Its totient is φ = 418964480.

The previous prime is 1165323277. The next prime is 1165323287. The reversal of 1165323280 is 823235611.

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (1165323287) 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 15 ways as a sum of consecutive naturals, for example, 70881 + ... + 85759.

It is an arithmetic number, because the mean of its divisors is an integer number (37363680).

Almost surely, 2^1165323280 is an apocalyptic number.

1165323280 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1165323280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1494547200).

1165323280 is an abundant number, since it is smaller than the sum of its proper divisors (1823771120).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1165323280 is a wasteful number, since it uses less digits than its factorization.

1165323280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14992 (or 14986 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 1165323280 is about 34136.8317217635. The cubic root of 1165323280 is about 1052.3223818845.

Adding to 1165323280 its reverse (823235611), we get a palindrome (1988558891).

The spelling of 1165323280 in words is "one billion, one hundred sixty-five million, three hundred twenty-three thousand, two hundred eighty".