217970398129 has 9 divisors (see below), whose sum is σ = 239592942169. Its totient is φ = 198150238660.

The previous prime is 217970398111. The next prime is 217970398141. The reversal of 217970398129 is 921893079712.

The square root of 217970398129 is 466873.

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

It is not a de Polignac number, because 217970398129 - 2⁷ = 217970398001 is a prime.

It is a super-2 number, since 2×217970398129² (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 (217970398109) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 5114382 + ... + 5156824.

Almost surely, 2^217970398129 is an apocalyptic number.

217970398129 is the 466873-rd square number.

217970398129 is the 233437-th centered octagonal number.

It is an amenable number.

217970398129 is a deficient number, since it is larger than the sum of its proper divisors (21622544040).

217970398129 is an frugal number, since it uses more digits than its factorization.

217970398129 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84908 (or 42454 counting only the distinct ones).

The product of its (nonzero) digits is 3429216, while the sum is 58.

The spelling of 217970398129 in words is "two hundred seventeen billion, nine hundred seventy million, three hundred ninety-eight thousand, one hundred twenty-nine".