1165724865 has 20 divisors (see below), whose sum is σ = 2089670484. Its totient is φ = 621719712.

The previous prime is 1165724821. The next prime is 1165724881. The reversal of 1165724865 is 5684275611.

1165724865 is a `hidden beast` number, since 1 + 16 + 572 + 4 + 8 + 65 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 692531856 + 473193009 = 26316^2 + 21753^2 .

It is not a de Polignac number, because 1165724865 - 2¹⁰ = 1165723841 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 1165724865.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1438762 + ... + 1439571.

Almost surely, 2^1165724865 is an apocalyptic number.

1165724865 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1165724865 is a deficient number, since it is larger than the sum of its proper divisors (923945619).

1165724865 is an equidigital number, since it uses as much as digits as its factorization.

1165724865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2878350 (or 2878341 counting only the distinct ones).

The product of its digits is 403200, while the sum is 45.

The square root of 1165724865 is about 34142.7132050164. The cubic root of 1165724865 is about 1052.4432491597.

The spelling of 1165724865 in words is "one billion, one hundred sixty-five million, seven hundred twenty-four thousand, eight hundred sixty-five".