3978664 has 32 divisors (see below), whose sum is σ = 7856640. Its totient is φ = 1886400.

The previous prime is 3978659. The next prime is 3978671. The reversal of 3978664 is 4668793.

3978664 = T₂₅ + T₂₆ + ... + T₂₈₇.

It is a happy number.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 3978664.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14997 + ... + 15259.

It is an arithmetic number, because the mean of its divisors is an integer number (245520).

Almost surely, 2^3978664 is an apocalyptic number.

It is an amenable number.

3978664 is a deficient number, since it is larger than the sum of its proper divisors (3877976).

3978664 is a wasteful number, since it uses less digits than its factorization.

3978664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 361 (or 357 counting only the distinct ones).

The product of its digits is 217728, while the sum is 43.

The square root of 3978664 is about 1994.6588680774. The cubic root of 3978664 is about 158.4573619748.

The spelling of 3978664 in words is "three million, nine hundred seventy-eight thousand, six hundred sixty-four".