172217715687668 has 18 divisors (see below), whose sum is σ = 350586064078866. Its totient is φ = 73807592437488.

The previous prime is 172217715687637. The next prime is 172217715687709. The reversal of 172217715687668 is 866786517712271.

It can be written as a sum of positive squares in only one way, i.e., 171618698510224 + 599017177444 = 13100332^2 + 773962^2 .

It is a junction number, because it is equal to n+sod(n) for n = 172217715687595 and 172217715687604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 439330907171 + ... + 439330907562.

It is an arithmetic number, because the mean of its divisors is an integer number (19477003559937).

Almost surely, 2^{172217715687668} is an apocalyptic number.

It is an amenable number.

172217715687668 is an abundant number, since it is smaller than the sum of its proper divisors (178368348391198).

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

172217715687668 is a wasteful number, since it uses less digits than its factorization.

172217715687668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 878661814751 (or 878661814742 counting only the distinct ones).

The product of its digits is 663828480, while the sum is 74.

The spelling of 172217715687668 in words is "one hundred seventy-two trillion, two hundred seventeen billion, seven hundred fifteen million, six hundred eighty-seven thousand, six hundred sixty-eight".