217213820136 has 48 divisors (see below), whose sum is σ = 588450959460. Its totient is φ = 72384480000.

The previous prime is 217213820093. The next prime is 217213820143. The reversal of 217213820136 is 631028312712.

It can be written as a sum of positive squares in 2 ways, for example, as 178599212100 + 38614608036 = 422610^2 + 196506^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 217213820136.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 157365 + ... + 677636.

Almost surely, 2^217213820136 is an apocalyptic number.

It is an amenable number.

217213820136 is an abundant number, since it is smaller than the sum of its proper divisors (371237139324).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

217213820136 is a wasteful number, since it uses less digits than its factorization.

217213820136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 838626 (or 838619 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The spelling of 217213820136 in words is "two hundred seventeen billion, two hundred thirteen million, eight hundred twenty thousand, one hundred thirty-six".