9688991 has 4 divisors (see below), whose sum is σ = 10434312. Its totient is φ = 8943672.

The previous prime is 9688981. The next prime is 9689021. The reversal of 9688991 is 1998869.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1998869 = 163 ⋅12263.

It is a cyclic number.

It is not a de Polignac number, because 9688991 - 2⁶ = 9688927 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 (9688951) 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, 372641 + ... + 372666.

It is an arithmetic number, because the mean of its divisors is an integer number (2608578).

Almost surely, 2^9688991 is an apocalyptic number.

9688991 is a deficient number, since it is larger than the sum of its proper divisors (745321).

9688991 is a wasteful number, since it uses less digits than its factorization.

9688991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 745320.

The product of its digits is 279936, while the sum is 50.

The square root of 9688991 is about 3112.7144102857. The cubic root of 9688991 is about 213.1864106105.

The spelling of 9688991 in words is "nine million, six hundred eighty-eight thousand, nine hundred ninety-one".