3978749 has 2 divisors, whose sum is σ = 3978750. Its totient is φ = 3978748.

The previous prime is 3978743. The next prime is 3978761. The reversal of 3978749 is 9478793.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3367225 + 611524 = 1835^2 + 782^2 .

It is an emirp because it is prime and its reverse (9478793) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 3978749 - 2²⁰ = 2930173 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3978743) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1989374 + 1989375.

It is an arithmetic number, because the mean of its divisors is an integer number (1989375).

Almost surely, 2^3978749 is an apocalyptic number.

It is an amenable number.

3978749 is a deficient number, since it is larger than the sum of its proper divisors (1).

3978749 is an equidigital number, since it uses as much as digits as its factorization.

3978749 is an evil number, because the sum of its binary digits is even.

The product of its digits is 381024, while the sum is 47.

The square root of 3978749 is about 1994.6801748651. The cubic root of 3978749 is about 158.4584903921.

The spelling of 3978749 in words is "three million, nine hundred seventy-eight thousand, seven hundred forty-nine".