3977665 has 4 divisors (see below), whose sum is σ = 4773204. Its totient is φ = 3182128.

The previous prime is 3977663. The next prime is 3977681. The reversal of 3977665 is 5667793.

3977665 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5667793 = 73 ⋅77641.

It can be written as a sum of positive squares in 2 ways, for example, as 2556801 + 1420864 = 1599^2 + 1192^2 .

It is a cyclic number.

It is not a de Polignac number, because 3977665 - 2¹ = 3977663 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3977663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 397762 + ... + 397771.

It is an arithmetic number, because the mean of its divisors is an integer number (1193301).

Almost surely, 2^3977665 is an apocalyptic number.

It is an amenable number.

3977665 is a deficient number, since it is larger than the sum of its proper divisors (795539).

3977665 is an equidigital number, since it uses as much as digits as its factorization.

3977665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 795538.

The product of its digits is 238140, while the sum is 43.

The square root of 3977665 is about 1994.4084335963. The cubic root of 3977665 is about 158.4440985481. Note that the first 3 decimals are identical.

The spelling of 3977665 in words is "three million, nine hundred seventy-seven thousand, six hundred sixty-five".