20617892217 has 12 divisors (see below), whose sum is σ = 32072276964. Its totient is φ = 12687933600.

The previous prime is 20617892159. The next prime is 20617892227. The reversal of 20617892217 is 71229871602.

It is a happy number.

20617892217 is a `hidden beast` number, since 2 + 0 + 617 + 8 + 9 + 2 + 21 + 7 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 2253305961 + 18364586256 = 47469^2 + 135516^2 .

It is not a de Polignac number, because 20617892217 - 2¹⁹ = 20617367929 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20617892227) 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 11 ways as a sum of consecutive naturals, for example, 88110534 + ... + 88110767.

It is an arithmetic number, because the mean of its divisors is an integer number (2672689747).

Almost surely, 2^20617892217 is an apocalyptic number.

It is an amenable number.

20617892217 is a deficient number, since it is larger than the sum of its proper divisors (11454384747).

20617892217 is a wasteful number, since it uses less digits than its factorization.

20617892217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 176221320 (or 176221317 counting only the distinct ones).

The product of its (nonzero) digits is 169344, while the sum is 45.

The spelling of 20617892217 in words is "twenty billion, six hundred seventeen million, eight hundred ninety-two thousand, two hundred seventeen".