9991013 has 4 divisors (see below), whose sum is σ = 9997548. Its totient is φ = 9984480.

The previous prime is 9990997. The next prime is 9991027. The reversal of 9991013 is 3101999.

9991013 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

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 2362369 + 7628644 = 1537^2 + 2762^2 .

It is a cyclic number.

It is not a de Polignac number, because 9991013 - 2⁴ = 9990997 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 (9991063) 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, 395 + ... + 4487.

It is an arithmetic number, because the mean of its divisors is an integer number (2499387).

Almost surely, 2^9991013 is an apocalyptic number.

It is an amenable number.

9991013 is a deficient number, since it is larger than the sum of its proper divisors (6535).

9991013 is a wasteful number, since it uses less digits than its factorization.

9991013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6534.

The product of its (nonzero) digits is 2187, while the sum is 32.

The square root of 9991013 is about 3160.8563713019. The cubic root of 9991013 is about 215.3789099777.

The spelling of 9991013 in words is "nine million, nine hundred ninety-one thousand, thirteen".