3978444817 has 2 divisors, whose sum is σ = 3978444818. Its totient is φ = 3978444816.

The previous prime is 3978444719. The next prime is 3978444823. The reversal of 3978444817 is 7184448793.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2200641921 + 1777802896 = 46911^2 + 42164^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3978444817 is a prime.

It is not a weakly prime, because it can be changed into another prime (3978444887) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1989222408 + 1989222409.

It is an arithmetic number, because the mean of its divisors is an integer number (1989222409).

Almost surely, 2^3978444817 is an apocalyptic number.

It is an amenable number.

3978444817 is a deficient number, since it is larger than the sum of its proper divisors (1).

3978444817 is an equidigital number, since it uses as much as digits as its factorization.

3978444817 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5419008, while the sum is 55.

The square root of 3978444817 is about 63074.9143241590. The cubic root of 3978444817 is about 1584.5445213730.

The spelling of 3978444817 in words is "three billion, nine hundred seventy-eight million, four hundred forty-four thousand, eight hundred seventeen".