3978423989 has 2 divisors, whose sum is σ = 3978423990. Its totient is φ = 3978423988.

The previous prime is 3978423949. The next prime is 3978424033. The reversal of 3978423989 is 9893248793.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2554493764 + 1423930225 = 50542^2 + 37735^2 .

It is a cyclic number.

It is not a de Polignac number, because 3978423989 - 2⁸ = 3978423733 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3978423949) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1989211994 + 1989211995.

It is an arithmetic number, because the mean of its divisors is an integer number (1989211995).

Almost surely, 2^3978423989 is an apocalyptic number.

It is an amenable number.

3978423989 is a deficient number, since it is larger than the sum of its proper divisors (1).

3978423989 is an equidigital number, since it uses as much as digits as its factorization.

3978423989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 23514624, while the sum is 62.

The square root of 3978423989 is about 63074.7492186850. The cubic root of 3978423989 is about 1584.5417562262.

The spelling of 3978423989 in words is "three billion, nine hundred seventy-eight million, four hundred twenty-three thousand, nine hundred eighty-nine".