9999391 has 8 divisors (see below), whose sum is σ = 10543104. Its totient is φ = 9469560.

The previous prime is 9999347. The next prime is 9999397. The reversal of 9999391 is 1939999.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 9999391 - 2¹³ = 9991199 is a prime.

It is a super-3 number, since 3×9999391³ (a number of 22 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9999397) 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 7 ways as a sum of consecutive naturals, for example, 1975 + ... + 4888.

It is an arithmetic number, because the mean of its divisors is an integer number (1317888).

Almost surely, 2^9999391 is an apocalyptic number.

9999391 is a deficient number, since it is larger than the sum of its proper divisors (543713).

9999391 is a wasteful number, since it uses less digits than its factorization.

9999391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6941.

The product of its digits is 177147, while the sum is 49.

The square root of 9999391 is about 3162.1813673475. The cubic root of 9999391 is about 215.4390954120.

The spelling of 9999391 in words is "nine million, nine hundred ninety-nine thousand, three hundred ninety-one".