217983470769 has 27 divisors (see below), whose sum is σ = 332349633369. Its totient is φ = 137656963080.

The previous prime is 217983470729. The next prime is 217983470773. The reversal of 217983470769 is 967074389712.

The square root of 217983470769 is 466887.

It is a perfect power (a square), and thus also a powerful number.

217983470769 is a `hidden beast` number, since 2 + 1 + 7 + 98 + 3 + 470 + 76 + 9 = 666.

It is not a de Polignac number, because 217983470769 - 2⁷ = 217983470641 is a prime.

It is a super-2 number, since 2×217983470769² (a number of 23 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (217983470729) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 26608464 + ... + 26616654.

Almost surely, 2^217983470769 is an apocalyptic number.

217983470769 is the 466887-th square number.

217983470769 is the 233444-th centered octagonal number.

It is an amenable number.

217983470769 is a deficient number, since it is larger than the sum of its proper divisors (114366162600).

217983470769 is an frugal number, since it uses more digits than its factorization.

217983470769 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16426 (or 8213 counting only the distinct ones).

The product of its (nonzero) digits is 32006016, while the sum is 63.

The spelling of 217983470769 in words is "two hundred seventeen billion, nine hundred eighty-three million, four hundred seventy thousand, seven hundred sixty-nine".