3990005 has 8 divisors (see below), whose sum is σ = 4836024. Its totient is φ = 3160000.

The previous prime is 3990001. The next prime is 3990011. The reversal of 3990005 is 5000993.

It can be written as a sum of positive squares in 4 ways, for example, as 1697809 + 2292196 = 1303^2 + 1514^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 3990005 - 2² = 3990001 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3990001) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3446 + ... + 4455.

It is an arithmetic number, because the mean of its divisors is an integer number (604503).

Almost surely, 2^3990005 is an apocalyptic number.

It is an amenable number.

3990005 is a deficient number, since it is larger than the sum of its proper divisors (846019).

3990005 is a wasteful number, since it uses less digits than its factorization.

3990005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8007.

The product of its (nonzero) digits is 1215, while the sum is 26.

The square root of 3990005 is about 1997.4996871089. The cubic root of 3990005 is about 158.6077776384.

Adding to 3990005 its reverse (5000993), we get a palindrome (8990998).

The spelling of 3990005 in words is "three million, nine hundred ninety thousand, five".