3991685626766 has 16 divisors (see below), whose sum is σ = 6152429976000. Its totient is φ = 1940929607520.

The previous prime is 3991685626723. The next prime is 3991685626823. The reversal of 3991685626766 is 6676265861993.

It is a Harshad number since it is a multiple of its sum of digits (74).

It is a junction number, because it is equal to n+sod(n) for n = 3991685626693 and 3991685626702.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13344245 + ... + 13640096.

It is an arithmetic number, because the mean of its divisors is an integer number (384526873500).

Almost surely, 2^{3991685626766} is an apocalyptic number.

3991685626766 is a deficient number, since it is larger than the sum of its proper divisors (2160744349234).

3991685626766 is a wasteful number, since it uses less digits than its factorization.

3991685626766 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26986379.

The product of its digits is 1058158080, while the sum is 74.

The spelling of 3991685626766 in words is "three trillion, nine hundred ninety-one billion, six hundred eighty-five million, six hundred twenty-six thousand, seven hundred sixty-six".