9991685626766 has 8 divisors (see below), whose sum is σ = 14988987395184. Its totient is φ = 4995356495040.

The previous prime is 9991685626733. The next prime is 9991685626799. The reversal of 9991685626766 is 6676265861999.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (9991685626733) and next prime (9991685626799).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 243133490 + ... + 243174581.

It is an arithmetic number, because the mean of its divisors is an integer number (1873623424398).

Almost surely, 2^{9991685626766} is an apocalyptic number.

9991685626766 is a deficient number, since it is larger than the sum of its proper divisors (4997301768418).

9991685626766 is a wasteful number, since it uses less digits than its factorization.

9991685626766 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 486318346.

The product of its digits is 3174474240, while the sum is 80.

The spelling of 9991685626766 in words is "nine trillion, nine hundred ninety-one billion, six hundred eighty-five million, six hundred twenty-six thousand, seven hundred sixty-six".