3951665 has 4 divisors (see below), whose sum is σ = 4742004. Its totient is φ = 3161328.

The previous prime is 3951611. The next prime is 3951707. The reversal of 3951665 is 5661593.

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 1024144 + 2927521 = 1012^2 + 1711^2 .

It is a cyclic number.

It is not a de Polignac number, because 3951665 - 2¹² = 3947569 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 395162 + ... + 395171.

It is an arithmetic number, because the mean of its divisors is an integer number (1185501).

Almost surely, 2^3951665 is an apocalyptic number.

It is an amenable number.

3951665 is a deficient number, since it is larger than the sum of its proper divisors (790339).

3951665 is an equidigital number, since it uses as much as digits as its factorization.

3951665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 790338.

The product of its digits is 24300, while the sum is 35.

The square root of 3951665 is about 1987.8795235124. The cubic root of 3951665 is about 158.0981204343.

The spelling of 3951665 in words is "three million, nine hundred fifty-one thousand, six hundred sixty-five".