9939846391 has 4 divisors (see below), whose sum is σ = 9941106672. Its totient is φ = 9938586112.

The previous prime is 9939846383. The next prime is 9939846401. The reversal of 9939846391 is 1936489399.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1936489399 = 13 ⋅148960723.

It is a cyclic number.

It is not a de Polignac number, because 9939846391 - 2³ = 9939846383 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 (9939846691) 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, 618235 + ... + 634108.

It is an arithmetic number, because the mean of its divisors is an integer number (2485276668).

Almost surely, 2^9939846391 is an apocalyptic number.

9939846391 is a deficient number, since it is larger than the sum of its proper divisors (1260281).

9939846391 is a wasteful number, since it uses less digits than its factorization.

9939846391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1260280.

The product of its digits is 11337408, while the sum is 61.

The square root of 9939846391 is about 99698.7782823842. The cubic root of 9939846391 is about 2150.1060983156.

The spelling of 9939846391 in words is "nine billion, nine hundred thirty-nine million, eight hundred forty-six thousand, three hundred ninety-one".