217929434845 has 24 divisors (see below), whose sum is σ = 276054662520. Its totient is φ = 165137080320.

The previous prime is 217929434819. The next prime is 217929434867. The reversal of 217929434845 is 548434929712.

It can be written as a sum of positive squares in 4 ways, for example, as 30941513604 + 186987921241 = 175902^2 + 432421^2 .

It is not a de Polignac number, because 217929434845 - 2³¹ = 215781951197 is a prime.

It is a super-3 number, since 3×217929434845³ (a number of 35 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 217929434845.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 16745701 + ... + 16758709.

It is an arithmetic number, because the mean of its divisors is an integer number (11502277605).

Almost surely, 2^217929434845 is an apocalyptic number.

It is an amenable number.

217929434845 is a deficient number, since it is larger than the sum of its proper divisors (58125227675).

217929434845 is a wasteful number, since it uses less digits than its factorization.

217929434845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22333 (or 22314 counting only the distinct ones).

The product of its digits is 17418240, while the sum is 58.

The spelling of 217929434845 in words is "two hundred seventeen billion, nine hundred twenty-nine million, four hundred thirty-four thousand, eight hundred forty-five".