217074923569 has 27 divisors (see below), whose sum is σ = 255428236011. Its totient is φ = 183942452400.

The previous prime is 217074923561. The next prime is 217074923579. The reversal of 217074923569 is 965329470712.

The square root of 217074923569 is 465913.

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

It can be written as a sum of positive squares in only one way, i.e., 208563015969 + 8511907600 = 456687^2 + 92260^2 .

It is not a de Polignac number, because 217074923569 - 2³ = 217074923561 is a prime.

It is a super-2 number, since 2×217074923569² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (217074923561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 329400162 + ... + 329400820.

Almost surely, 2^217074923569 is an apocalyptic number.

217074923569 is the 465913-rd square number.

217074923569 is the 232957-th centered octagonal number.

It is an amenable number.

217074923569 is a deficient number, since it is larger than the sum of its proper divisors (38353312442).

217074923569 is an frugal number, since it uses more digits than its factorization.

217074923569 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1534 (or 767 counting only the distinct ones).

The product of its (nonzero) digits is 5715360, while the sum is 55.

The spelling of 217074923569 in words is "two hundred seventeen billion, seventy-four million, nine hundred twenty-three thousand, five hundred sixty-nine".