217160660025 has 81 divisors (see below), whose sum is σ = 398012806893. Its totient is φ = 113183294400.

The previous prime is 217160659981. The next prime is 217160660047. The reversal of 217160660025 is 520066061712.

It is a happy number.

The square root of 217160660025 is 466005.

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

217160660025 is a `hidden beast` number, since 2 + 17 + 16 + 0 + 6 + 600 + 25 = 666.

217160660025 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 6391522809 + 210769137216 = 79947^2 + 459096^2 .

It is not a de Polignac number, because 217160660025 - 2⁷ = 217160659897 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 328533195 + ... + 328533855.

Almost surely, 2^217160660025 is an apocalyptic number.

217160660025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

217160660025 is the 466005-th square number.

217160660025 is the 233003-rd centered octagonal number.

It is an amenable number.

217160660025 is a deficient number, since it is larger than the sum of its proper divisors (180852146868).

217160660025 is an frugal number, since it uses more digits than its factorization.

217160660025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1432 (or 716 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

Multiplying 217160660025 by its sum of digits (36), we get a square (7817783760900 = 2796030²).

The spelling of 217160660025 in words is "two hundred seventeen billion, one hundred sixty million, six hundred sixty thousand, twenty-five".