3978194615971 has 2 divisors, whose sum is σ = 3978194615972. Its totient is φ = 3978194615970.

The previous prime is 3978194615953. The next prime is 3978194616031. The reversal of 3978194615971 is 1795164918793.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 3978194615971 - 2¹¹ = 3978194613923 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 3978194615971.

It is not a weakly prime, because it can be changed into another prime (3978194615671) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1989097307985 + 1989097307986.

It is an arithmetic number, because the mean of its divisors is an integer number (1989097307986).

Almost surely, 2^{3978194615971} is an apocalyptic number.

3978194615971 is a deficient number, since it is larger than the sum of its proper divisors (1).

3978194615971 is an equidigital number, since it uses as much as digits as its factorization.

3978194615971 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 102876480, while the sum is 70.

The spelling of 3978194615971 in words is "three trillion, nine hundred seventy-eight billion, one hundred ninety-four million, six hundred fifteen thousand, nine hundred seventy-one".