1205500009 has 12 divisors (see below), whose sum is σ = 1402888788. Its totient is φ = 1032864000.

The previous prime is 1205500003. The next prime is 1205500013. The reversal of 1205500009 is 9000055021.

It can be written as a sum of positive squares in 2 ways, for example, as 1186113600 + 19386409 = 34440^2 + 4403^2 .

It is not a de Polignac number, because 1205500009 - 2¹⁷ = 1205368937 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1205500003) 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 11 ways as a sum of consecutive naturals, for example, 204909 + ... + 210709.

It is an arithmetic number, because the mean of its divisors is an integer number (116907399).

Almost surely, 2^1205500009 is an apocalyptic number.

It is an amenable number.

1205500009 is a deficient number, since it is larger than the sum of its proper divisors (197388779).

1205500009 is an equidigital number, since it uses as much as digits as its factorization.

1205500009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10056 (or 10049 counting only the distinct ones).

The product of its (nonzero) digits is 450, while the sum is 22.

The square root of 1205500009 is about 34720.3111881216. The cubic root of 1205500009 is about 1064.2796039184.

The spelling of 1205500009 in words is "one billion, two hundred five million, five hundred thousand, nine".