9999785539879 has 2 divisors, whose sum is σ = 9999785539880. Its totient is φ = 9999785539878.

The previous prime is 9999785539859. The next prime is 9999785539921. The reversal of 9999785539879 is 9789355879999.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 9999785539879 - 2²³ = 9999777151271 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9999785539859) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4999892769939 + 4999892769940.

It is an arithmetic number, because the mean of its divisors is an integer number (4999892769940).

Almost surely, 2^{9999785539879} is an apocalyptic number.

9999785539879 is a deficient number, since it is larger than the sum of its proper divisors (1).

9999785539879 is an equidigital number, since it uses as much as digits as its factorization.

9999785539879 is an evil number, because the sum of its binary digits is even.

The product of its digits is 124994923200, while the sum is 97.

The spelling of 9999785539879 in words is "nine trillion, nine hundred ninety-nine billion, seven hundred eighty-five million, five hundred thirty-nine thousand, eight hundred seventy-nine".