989985617 has 2 divisors, whose sum is σ = 989985618. Its totient is φ = 989985616.

The previous prime is 989985613. The next prime is 989985643. The reversal of 989985617 is 716589989.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 758671936 + 231313681 = 27544^2 + 15209^2 .

It is a cyclic number.

It is not a de Polignac number, because 989985617 - 2² = 989985613 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 989985617.

It is not a weakly prime, because it can be changed into another prime (989985613) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 494992808 + 494992809.

It is an arithmetic number, because the mean of its divisors is an integer number (494992809).

Almost surely, 2^989985617 is an apocalyptic number.

It is an amenable number.

989985617 is a deficient number, since it is larger than the sum of its proper divisors (1).

989985617 is an equidigital number, since it uses as much as digits as its factorization.

989985617 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9797760, while the sum is 62.

The square root of 989985617 is about 31464.0368834007. The cubic root of 989985617 is about 996.6506668249.

The spelling of 989985617 in words is "nine hundred eighty-nine million, nine hundred eighty-five thousand, six hundred seventeen".