9991613 has 6 divisors (see below), whose sum is σ = 10186554. Its totient is φ = 9800336.

The previous prime is 9991603. The next prime is 9991649. The reversal of 9991613 is 3161999.

It can be written as a sum of positive squares in 3 ways, for example, as 1570009 + 8421604 = 1253^2 + 2902^2 .

It is not a de Polignac number, because 9991613 - 2⁸ = 9991357 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 (9991603) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1031 + ... + 4587.

It is an arithmetic number, because the mean of its divisors is an integer number (1697759).

Almost surely, 2^9991613 is an apocalyptic number.

It is an amenable number.

9991613 is a deficient number, since it is larger than the sum of its proper divisors (194941).

9991613 is an equidigital number, since it uses as much as digits as its factorization.

9991613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3663 (or 3610 counting only the distinct ones).

The product of its digits is 13122, while the sum is 38.

The square root of 9991613 is about 3160.9512808647. The cubic root of 9991613 is about 215.3832213443.

The spelling of 9991613 in words is "nine million, nine hundred ninety-one thousand, six hundred thirteen".