3990442 has 4 divisors (see below), whose sum is σ = 5985666. Its totient is φ = 1995220.

The previous prime is 3990419. The next prime is 3990449. The reversal of 3990442 is 2440993.

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., 3806401 + 184041 = 1951^2 + 429^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a nialpdrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (3990449) 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 as a sum of consecutive naturals, namely, 997609 + ... + 997612.

Almost surely, 2^3990442 is an apocalyptic number.

3990442 is a deficient number, since it is larger than the sum of its proper divisors (1995224).

3990442 is a wasteful number, since it uses less digits than its factorization.

3990442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1995223.

The product of its (nonzero) digits is 7776, while the sum is 31.

The square root of 3990442 is about 1997.6090708645. The cubic root of 3990442 is about 158.6135678625.

The spelling of 3990442 in words is "three million, nine hundred ninety thousand, four hundred forty-two".