3989978 has 4 divisors (see below), whose sum is σ = 5984970. Its totient is φ = 1994988.

The previous prime is 3989963. The next prime is 3989983. The reversal of 3989978 is 8799893.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 8799893 = 661 ⋅13313.

It can be written as a sum of positive squares in only one way, i.e., 2229049 + 1760929 = 1493^2 + 1327^2 .

It is a Curzon number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 997493 + ... + 997496.

Almost surely, 2^3989978 is an apocalyptic number.

3989978 is a deficient number, since it is larger than the sum of its proper divisors (1994992).

3989978 is a wasteful number, since it uses less digits than its factorization.

3989978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1994991.

The product of its digits is 979776, while the sum is 53.

The square root of 3989978 is about 1997.4929286483. The cubic root of 3989978 is about 158.6074198762.

The spelling of 3989978 in words is "three million, nine hundred eighty-nine thousand, nine hundred seventy-eight".