3990605 has 4 divisors (see below), whose sum is σ = 4788732. Its totient is φ = 3192480.

The previous prime is 3990601. The next prime is 3990607. The reversal of 3990605 is 5060993.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1841449 + 2149156 = 1357^2 + 1466^2 .

It is not a de Polignac number, because 3990605 - 2² = 3990601 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 (3990601) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 399056 + ... + 399065.

It is an arithmetic number, because the mean of its divisors is an integer number (1197183).

Almost surely, 2^3990605 is an apocalyptic number.

It is an amenable number.

3990605 is a deficient number, since it is larger than the sum of its proper divisors (798127).

3990605 is an equidigital number, since it uses as much as digits as its factorization.

3990605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 798126.

The product of its (nonzero) digits is 7290, while the sum is 32.

The square root of 3990605 is about 1997.6498692213. The cubic root of 3990605 is about 158.6157274945.

The spelling of 3990605 in words is "three million, nine hundred ninety thousand, six hundred five".