3978739 has 2 divisors, whose sum is σ = 3978740. Its totient is φ = 3978738.

The previous prime is 3978727. The next prime is 3978743. The reversal of 3978739 is 9378793.

It is a strong prime.

It is an emirp because it is prime and its reverse (9378793) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 3978739 - 2⁵ = 3978707 is a prime.

3978739 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (3978749) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1989369 + 1989370.

It is an arithmetic number, because the mean of its divisors is an integer number (1989370).

Almost surely, 2^3978739 is an apocalyptic number.

3978739 is a deficient number, since it is larger than the sum of its proper divisors (1).

3978739 is an equidigital number, since it uses as much as digits as its factorization.

3978739 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 285768, while the sum is 46.

The square root of 3978739 is about 1994.6776681960. The cubic root of 3978739 is about 158.4583576380.

The spelling of 3978739 in words is "three million, nine hundred seventy-eight thousand, seven hundred thirty-nine".