3996665 has 4 divisors (see below), whose sum is σ = 4796004. Its totient is φ = 3197328.

The previous prime is 3996653. The next prime is 3996743. The reversal of 3996665 is 5666993.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5666993 = 23 ⋅246391.

It can be written as a sum of positive squares in 2 ways, for example, as 1048576 + 2948089 = 1024^2 + 1717^2 .

It is a cyclic number.

It is not a de Polignac number, because 3996665 - 2¹⁴ = 3980281 is a prime.

It is a super-2 number, since 2×3996665² = 31946662244450, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 399662 + ... + 399671.

It is an arithmetic number, because the mean of its divisors is an integer number (1199001).

Almost surely, 2^3996665 is an apocalyptic number.

It is an amenable number.

3996665 is a deficient number, since it is larger than the sum of its proper divisors (799339).

3996665 is an equidigital number, since it uses as much as digits as its factorization.

3996665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 799338.

The product of its digits is 262440, while the sum is 44.

The square root of 3996665 is about 1999.1660761428. The cubic root of 3996665 is about 158.6959764095.

The spelling of 3996665 in words is "three million, nine hundred ninety-six thousand, six hundred sixty-five".