391659809947 has 16 divisors (see below), whose sum is σ = 470047583232. Its totient is φ = 319067068320.

The previous prime is 391659809887. The next prime is 391659809977. The reversal of 391659809947 is 749908956193.

It is not a de Polignac number, because 391659809947 - 2¹¹ = 391659807899 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (391659809977) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7722079 + ... + 7772632.

It is an arithmetic number, because the mean of its divisors is an integer number (29377973952).

Almost surely, 2^391659809947 is an apocalyptic number.

391659809947 is a deficient number, since it is larger than the sum of its proper divisors (78387773285).

391659809947 is a wasteful number, since it uses less digits than its factorization.

391659809947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15494898.

The product of its (nonzero) digits is 132269760, while the sum is 70.

The spelling of 391659809947 in words is "three hundred ninety-one billion, six hundred fifty-nine million, eight hundred nine thousand, nine hundred forty-seven".