215505009 has 32 divisors (see below), whose sum is σ = 338668800. Its totient is φ = 135146880.

The previous prime is 215505007. The next prime is 215505023. The reversal of 215505009 is 900505512.

215505009 is a `hidden beast` number, since 2 + 155 + 0 + 500 + 9 = 666.

It is not a de Polignac number, because 215505009 - 2¹ = 215505007 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (215505007) 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 31 ways as a sum of consecutive naturals, for example, 35037 + ... + 40725.

It is an arithmetic number, because the mean of its divisors is an integer number (10583400).

Almost surely, 2^215505009 is an apocalyptic number.

It is an amenable number.

215505009 is a deficient number, since it is larger than the sum of its proper divisors (123163791).

215505009 is a wasteful number, since it uses less digits than its factorization.

215505009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5782 (or 5776 counting only the distinct ones).

The product of its (nonzero) digits is 2250, while the sum is 27.

The square root of 215505009 is about 14680.0888621289. The cubic root of 215505009 is about 599.5413244506.

The spelling of 215505009 in words is "two hundred fifteen million, five hundred five thousand, nine".