1155565009 has 4 divisors (see below), whose sum is σ = 1216384240. Its totient is φ = 1094745780.

The previous prime is 1155564967. The next prime is 1155565027. The reversal of 1155565009 is 9005655511.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1155565009 - 2⁹ = 1155564497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1155565039) 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, 30409587 + ... + 30409624.

It is an arithmetic number, because the mean of its divisors is an integer number (304096060).

Almost surely, 2^1155565009 is an apocalyptic number.

1155565009 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

1155565009 is a deficient number, since it is larger than the sum of its proper divisors (60819231).

1155565009 is an equidigital number, since it uses as much as digits as its factorization.

1155565009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60819230.

The product of its (nonzero) digits is 33750, while the sum is 37.

The square root of 1155565009 is about 33993.6024716416. The cubic root of 1155565009 is about 1049.3768060088.

The spelling of 1155565009 in words is "one billion, one hundred fifty-five million, five hundred sixty-five thousand, nine".