9558991 has 4 divisors (see below), whose sum is σ = 10294312. Its totient is φ = 8823672.

The previous prime is 9558979. The next prime is 9559013. The reversal of 9558991 is 1998559.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 9558991 - 2⁵ = 9558959 is a prime.

It is a Duffinian number.

9558991 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9558931) 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, 367641 + ... + 367666.

It is an arithmetic number, because the mean of its divisors is an integer number (2573578).

Almost surely, 2^9558991 is an apocalyptic number.

9558991 is a deficient number, since it is larger than the sum of its proper divisors (735321).

9558991 is a wasteful number, since it uses less digits than its factorization.

9558991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 735320.

The product of its digits is 145800, while the sum is 46.

The square root of 9558991 is about 3091.7617954817. The cubic root of 9558991 is about 212.2286529650.

The spelling of 9558991 in words is "nine million, five hundred fifty-eight thousand, nine hundred ninety-one".