3990631 has 4 divisors (see below), whose sum is σ = 4225392. Its totient is φ = 3755872.

The previous prime is 3990619. The next prime is 3990641. The reversal of 3990631 is 1360993.

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

It is a cyclic number.

It is not a de Polignac number, because 3990631 - 2¹¹ = 3988583 is a prime.

It is a super-2 number, since 2×3990631² = 31850271556322, which contains 22 as substring.

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 Duffinian number.

3990631 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 3990593 and 3990602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3990601) 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 in 3 ways as a sum of consecutive naturals, for example, 117355 + ... + 117388.

It is an arithmetic number, because the mean of its divisors is an integer number (1056348).

Almost surely, 2^3990631 is an apocalyptic number.

3990631 is a deficient number, since it is larger than the sum of its proper divisors (234761).

3990631 is a wasteful number, since it uses less digits than its factorization.

3990631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 234760.

The product of its (nonzero) digits is 4374, while the sum is 31.

The square root of 3990631 is about 1997.6563768576. The cubic root of 3990631 is about 158.6160719703.

The spelling of 3990631 in words is "three million, nine hundred ninety thousand, six hundred thirty-one".