3978661 has 8 divisors (see below), whose sum is σ = 4134944. Its totient is φ = 3825360.

The previous prime is 3978659. The next prime is 3978671. The reversal of 3978661 is 1668793.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 3978661 - 2¹ = 3978659 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3978641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2191 + ... + 3571.

It is an arithmetic number, because the mean of its divisors is an integer number (516868).

Almost surely, 2^3978661 is an apocalyptic number.

It is an amenable number.

3978661 is a deficient number, since it is larger than the sum of its proper divisors (156283).

3978661 is a wasteful number, since it uses less digits than its factorization.

3978661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1491.

The product of its digits is 54432, while the sum is 40.

The square root of 3978661 is about 1994.6581160690. The cubic root of 3978661 is about 158.4573221481.

The spelling of 3978661 in words is "three million, nine hundred seventy-eight thousand, six hundred sixty-one".