9979813 has 4 divisors (see below), whose sum is σ = 9990508. Its totient is φ = 9969120.

The previous prime is 9979811. The next prime is 9979817. The reversal of 9979813 is 3189799.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 4133089 + 5846724 = 2033^2 + 2418^2 .

It is a cyclic number.

It is not a de Polignac number, because 9979813 - 2¹ = 9979811 is a prime.

It is a Duffinian number.

9979813 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9979811) 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, 3798 + ... + 5863.

It is an arithmetic number, because the mean of its divisors is an integer number (2497627).

Almost surely, 2^9979813 is an apocalyptic number.

It is an amenable number.

9979813 is a deficient number, since it is larger than the sum of its proper divisors (10695).

9979813 is a wasteful number, since it uses less digits than its factorization.

9979813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10694.

The product of its digits is 122472, while the sum is 46.

The square root of 9979813 is about 3159.0842027398. The cubic root of 9979813 is about 215.2983994317.

The spelling of 9979813 in words is "nine million, nine hundred seventy-nine thousand, eight hundred thirteen".