3949978 has 4 divisors (see below), whose sum is σ = 5924970. Its totient is φ = 1974988.

The previous prime is 3949969. The next prime is 3950029. The reversal of 3949978 is 8799493.

3949978 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 3932289 + 17689 = 1983^2 + 133^2 .

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an Ulam number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 987493 + ... + 987496.

Almost surely, 2^3949978 is an apocalyptic number.

3949978 is a deficient number, since it is larger than the sum of its proper divisors (1974992).

3949978 is a wasteful number, since it uses less digits than its factorization.

3949978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1974991.

The product of its digits is 489888, while the sum is 49.

The square root of 3949978 is about 1987.4551567268. The cubic root of 3949978 is about 158.0756194132.

The spelling of 3949978 in words is "three million, nine hundred forty-nine thousand, nine hundred seventy-eight".