989969917 has 2 divisors, whose sum is σ = 989969918. Its totient is φ = 989969916.

The previous prime is 989969861. The next prime is 989969947. The reversal of 989969917 is 719969989.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 839318841 + 150651076 = 28971^2 + 12274^2 .

It is a cyclic number.

It is not a de Polignac number, because 989969917 - 2¹⁹ = 989445629 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (989969947) 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, 494984958 + 494984959.

It is an arithmetic number, because the mean of its divisors is an integer number (494984959).

Almost surely, 2^989969917 is an apocalyptic number.

It is an amenable number.

989969917 is a deficient number, since it is larger than the sum of its proper divisors (1).

989969917 is an equidigital number, since it uses as much as digits as its factorization.

989969917 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 19840464, while the sum is 67.

The square root of 989969917 is about 31463.7873912217. The cubic root of 989969917 is about 996.6453982305.

The spelling of 989969917 in words is "nine hundred eighty-nine million, nine hundred sixty-nine thousand, nine hundred seventeen".