9785678991 has 16 divisors (see below), whose sum is σ = 14241918720. Its totient is φ = 5927296320.

The previous prime is 9785678983. The next prime is 9785679023. The reversal of 9785678991 is 1998765879.

9785678991 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 9785678991 - 2³ = 9785678983 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9785673991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26731 + ... + 142428.

It is an arithmetic number, because the mean of its divisors is an integer number (890119920).

Almost surely, 2^9785678991 is an apocalyptic number.

9785678991 is a deficient number, since it is larger than the sum of its proper divisors (4456239729).

9785678991 is a wasteful number, since it uses less digits than its factorization.

9785678991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170926.

The product of its digits is 68584320, while the sum is 69.

The square root of 9785678991 is about 98922.5909031906. The cubic root of 9785678991 is about 2138.9320515707.

The spelling of 9785678991 in words is "nine billion, seven hundred eighty-five million, six hundred seventy-eight thousand, nine hundred ninety-one".