3978561 has 16 divisors (see below), whose sum is σ = 5660928. Its totient is φ = 2476800.

The previous prime is 3978553. The next prime is 3978587. The reversal of 3978561 is 1658793.

3978561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 3978561 - 2³ = 3978553 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3978511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9016 + ... + 9446.

It is an arithmetic number, because the mean of its divisors is an integer number (353808).

Almost surely, 2^3978561 is an apocalyptic number.

It is an amenable number.

3978561 is a deficient number, since it is larger than the sum of its proper divisors (1682367).

3978561 is a wasteful number, since it uses less digits than its factorization.

3978561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 632.

The product of its digits is 45360, while the sum is 39.

The square root of 3978561 is about 1994.6330489591. The cubic root of 3978561 is about 158.4559945771.

The spelling of 3978561 in words is "three million, nine hundred seventy-eight thousand, five hundred sixty-one".