990988717 has 4 divisors (see below), whose sum is σ = 991051740. Its totient is φ = 990925696.

The previous prime is 990988711. The next prime is 990988727. The reversal of 990988717 is 717889099.

990988717 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 717889099 = 16979 ⋅42281.

It can be written as a sum of positive squares in 2 ways, for example, as 888695721 + 102292996 = 29811^2 + 10114^2 .

It is a cyclic number.

It is not a de Polignac number, because 990988717 - 2⁷ = 990988589 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (990988711) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13659 + ... + 46567.

It is an arithmetic number, because the mean of its divisors is an integer number (247762935).

Almost surely, 2^990988717 is an apocalyptic number.

It is an amenable number.

990988717 is a deficient number, since it is larger than the sum of its proper divisors (63023).

990988717 is a wasteful number, since it uses less digits than its factorization.

990988717 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63022.

The product of its (nonzero) digits is 2286144, while the sum is 58.

The square root of 990988717 is about 31479.9732687307. The cubic root of 990988717 is about 996.9871709772.

It can be divided in two parts, 9909887 and 17, that added together give a square (9909904 = 3148²).

The spelling of 990988717 in words is "nine hundred ninety million, nine hundred eighty-eight thousand, seven hundred seventeen".