217968956 has 48 divisors (see below), whose sum is σ = 403038720. Its totient is φ = 103044480.

The previous prime is 217968943. The next prime is 217968973. The reversal of 217968956 is 659869712.

Its product of digits (1632960) is a multiple of the sum of its prime divisors (432).

It is a junction number, because it is equal to n+sod(n) for n = 217968898 and 217968907.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 911885 + ... + 912123.

It is an arithmetic number, because the mean of its divisors is an integer number (8396640).

Almost surely, 2^217968956 is an apocalyptic number.

It is an amenable number.

217968956 is a deficient number, since it is larger than the sum of its proper divisors (185069764).

217968956 is a wasteful number, since it uses less digits than its factorization.

217968956 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 434 (or 432 counting only the distinct ones).

The product of its digits is 1632960, while the sum is 53.

The square root of 217968956 is about 14763.7717403108. The cubic root of 217968956 is about 601.8175957569.

The spelling of 217968956 in words is "two hundred seventeen million, nine hundred sixty-eight thousand, nine hundred fifty-six".