989715217 has 2 divisors, whose sum is σ = 989715218. Its totient is φ = 989715216.

The previous prime is 989715173. The next prime is 989715289. The reversal of 989715217 is 712517989.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 800267521 + 189447696 = 28289^2 + 13764^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-989715217 is a prime.

It is a super-2 number, since 2×989715217² = 1959072421522714178, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (989715017) by changing a digit.

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 as a sum of consecutive naturals, namely, 494857608 + 494857609.

It is an arithmetic number, because the mean of its divisors is an integer number (494857609).

Almost surely, 2^989715217 is an apocalyptic number.

It is an amenable number.

989715217 is a deficient number, since it is larger than the sum of its proper divisors (1).

989715217 is an equidigital number, since it uses as much as digits as its factorization.

989715217 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 317520, while the sum is 49.

The square root of 989715217 is about 31459.7396206644. The cubic root of 989715217 is about 996.5599184088.

The spelling of 989715217 in words is "nine hundred eighty-nine million, seven hundred fifteen thousand, two hundred seventeen".