217161163878388 has 6 divisors (see below), whose sum is σ = 380032036787186. Its totient is φ = 108580581939192.

The previous prime is 217161163878367. The next prime is 217161163878401. The reversal of 217161163878388 is 883878361161712.

It can be written as a sum of positive squares in only one way, i.e., 118736153078544 + 98425010799844 = 10896612^2 + 9920938^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27145145484795 + ... + 27145145484802.

Almost surely, 2^{217161163878388} is an apocalyptic number.

It is an amenable number.

217161163878388 is a deficient number, since it is larger than the sum of its proper divisors (162870872908798).

217161163878388 is a wasteful number, since it uses less digits than its factorization.

217161163878388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54290290969601 (or 54290290969599 counting only the distinct ones).

The product of its digits is 130056192, while the sum is 70.

The spelling of 217161163878388 in words is "two hundred seventeen trillion, one hundred sixty-one billion, one hundred sixty-three million, eight hundred seventy-eight thousand, three hundred eighty-eight".