9999979686 has 32 divisors (see below), whose sum is σ = 22641469920. Its totient is φ = 3270432672.

The previous prime is 9999979657. The next prime is 9999979727. The reversal of 9999979686 is 6869799999.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1744165 + ... + 1749888.

It is an arithmetic number, because the mean of its divisors is an integer number (707545935).

Almost surely, 2^9999979686 is an apocalyptic number.

9999979686 is an abundant number, since it is smaller than the sum of its proper divisors (12641490234).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

9999979686 is a wasteful number, since it uses less digits than its factorization.

9999979686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3494117 (or 3494111 counting only the distinct ones).

The product of its digits is 1071385056, while the sum is 81.

The square root of 9999979686 is about 99999.8984299484. The cubic root of 9999979686 is about 2154.4332311914.

The spelling of 9999979686 in words is "nine billion, nine hundred ninety-nine million, nine hundred seventy-nine thousand, six hundred eighty-six".