3978391839 has 4 divisors (see below), whose sum is σ = 5304522456. Its totient is φ = 2652261224.

The previous prime is 3978391801. The next prime is 3978391843. The reversal of 3978391839 is 9381938793.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 3978391839 - 2²¹ = 3976294687 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3978392839) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 663065304 + ... + 663065309.

It is an arithmetic number, because the mean of its divisors is an integer number (1326130614).

Almost surely, 2^3978391839 is an apocalyptic number.

3978391839 is a deficient number, since it is larger than the sum of its proper divisors (1326130617).

3978391839 is a wasteful number, since it uses less digits than its factorization.

3978391839 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1326130616.

The product of its digits is 8817984, while the sum is 60.

The square root of 3978391839 is about 63074.4943618258. The cubic root of 3978391839 is about 1584.5374879402.

The spelling of 3978391839 in words is "three billion, nine hundred seventy-eight million, three hundred ninety-one thousand, eight hundred thirty-nine".