990917 has 2 divisors, whose sum is σ = 990918. Its totient is φ = 990916.

The previous prime is 990893. The next prime is 990923. The reversal of 990917 is 719099.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 982081 + 8836 = 991^2 + 94^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-990917 is a prime.

It is a Chen prime.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 990917.

It is not a weakly prime, because it can be changed into another prime (990967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495458 + 495459.

It is an arithmetic number, because the mean of its divisors is an integer number (495459).

2⁹⁹⁰⁹¹⁷ is an apocalyptic number.

It is an amenable number.

990917 is a deficient number, since it is larger than the sum of its proper divisors (1).

990917 is an equidigital number, since it uses as much as digits as its factorization.

990917 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5103, while the sum is 35.

The square root of 990917 is about 995.4481402866. The cubic root of 990917 is about 99.6963120029.

The spelling of 990917 in words is "nine hundred ninety thousand, nine hundred seventeen".