1156009565 has 4 divisors (see below), whose sum is σ = 1387211484. Its totient is φ = 924807648.

The previous prime is 1156009559. The next prime is 1156009567. The reversal of 1156009565 is 5659006511.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 373185124 + 782824441 = 19318^2 + 27979^2 .

It is a cyclic number.

It is not a de Polignac number, because 1156009565 - 2¹⁶ = 1155944029 is a prime.

It is a super-2 number, since 2×1156009565² = 2672716228742978450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1156009567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 115600952 + ... + 115600961.

It is an arithmetic number, because the mean of its divisors is an integer number (346802871).

Almost surely, 2^1156009565 is an apocalyptic number.

It is an amenable number.

1156009565 is a deficient number, since it is larger than the sum of its proper divisors (231201919).

1156009565 is an equidigital number, since it uses as much as digits as its factorization.

1156009565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 231201918.

The product of its (nonzero) digits is 40500, while the sum is 38.

The square root of 1156009565 is about 34000.1406614737. The cubic root of 1156009565 is about 1049.5113569115.

The spelling of 1156009565 in words is "one billion, one hundred fifty-six million, nine thousand, five hundred sixty-five".