215512088909 has 6 divisors (see below), whose sum is σ = 233365161546. Its totient is φ = 198934235760.

The previous prime is 215512088893. The next prime is 215512088921. The reversal of 215512088909 is 909880215512.

It can be written as a sum of positive squares in 3 ways, for example, as 21551120809 + 193960968100 = 146803^2 + 440410^2 .

It is not a de Polignac number, because 215512088909 - 2⁴ = 215512088893 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215512088969) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 637609562 + ... + 637609899.

It is an arithmetic number, because the mean of its divisors is an integer number (38894193591).

Almost surely, 2^215512088909 is an apocalyptic number.

It is an amenable number.

215512088909 is a deficient number, since it is larger than the sum of its proper divisors (17853072637).

215512088909 is a wasteful number, since it uses less digits than its factorization.

215512088909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1275219487 (or 1275219474 counting only the distinct ones).

The product of its (nonzero) digits is 518400, while the sum is 50.

The spelling of 215512088909 in words is "two hundred fifteen billion, five hundred twelve million, eighty-eight thousand, nine hundred nine".