9658991 has 4 divisors (see below), whose sum is σ = 9701400. Its totient is φ = 9616584.

The previous prime is 9658967. The next prime is 9658993. The reversal of 9658991 is 1998569.

9658991 is digitally balanced in base 3, 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.

It is a cyclic number.

It is not a de Polignac number, because 9658991 - 2⁶ = 9658927 is a prime.

It is a super-2 number, since 2×9658991² = 186592214276162, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9658993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20861 + ... + 21318.

It is an arithmetic number, because the mean of its divisors is an integer number (2425350).

Almost surely, 2^9658991 is an apocalyptic number.

9658991 is a deficient number, since it is larger than the sum of its proper divisors (42409).

9658991 is a wasteful number, since it uses less digits than its factorization.

9658991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42408.

The product of its digits is 174960, while the sum is 47.

The square root of 9658991 is about 3107.8917291309. The cubic root of 9658991 is about 212.9661535998.

The spelling of 9658991 in words is "nine million, six hundred fifty-eight thousand, nine hundred ninety-one".