9979591 has 4 divisors (see below), whose sum is σ = 10023400. Its totient is φ = 9935784.

The previous prime is 9979577. The next prime is 9979609. The reversal of 9979591 is 1959799.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9979591 is a prime.

It is a Duffinian number.

9979591 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9979511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21561 + ... + 22018.

It is an arithmetic number, because the mean of its divisors is an integer number (2505850).

Almost surely, 2^9979591 is an apocalyptic number.

9979591 is a deficient number, since it is larger than the sum of its proper divisors (43809).

9979591 is a wasteful number, since it uses less digits than its factorization.

9979591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43808.

The product of its digits is 229635, while the sum is 49.

The square root of 9979591 is about 3159.0490657791. The cubic root of 9979591 is about 215.2968029890.

The spelling of 9979591 in words is "nine million, nine hundred seventy-nine thousand, five hundred ninety-one".