9855338991 has 24 divisors (see below), whose sum is σ = 14409214464. Its totient is φ = 5984250240.

The previous prime is 9855338989. The next prime is 9855339037. The reversal of 9855338991 is 1998335589.

It is a happy number.

It is not a de Polignac number, because 9855338991 - 2¹ = 9855338989 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9855338951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 156465 + ... + 210218.

It is an arithmetic number, because the mean of its divisors is an integer number (600383936).

Almost surely, 2^9855338991 is an apocalyptic number.

9855338991 is a deficient number, since it is larger than the sum of its proper divisors (4553875473).

9855338991 is a wasteful number, since it uses less digits than its factorization.

9855338991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 366751 (or 366734 counting only the distinct ones).

The product of its digits is 10497600, while the sum is 60.

The square root of 9855338991 is about 99274.0600106594. The cubic root of 9855338991 is about 2143.9954320389.

The spelling of 9855338991 in words is "nine billion, eight hundred fifty-five million, three hundred thirty-eight thousand, nine hundred ninety-one".