3953665 has 4 divisors (see below), whose sum is σ = 4744404. Its totient is φ = 3162928.

The previous prime is 3953629. The next prime is 3953669. The reversal of 3953665 is 5663593.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5663593 = 13 ⋅435661.

It can be written as a sum of positive squares in 2 ways, for example, as 1498176 + 2455489 = 1224^2 + 1567^2 .

It is a cyclic number.

It is not a de Polignac number, because 3953665 - 2¹⁷ = 3822593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3953669) 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, 395362 + ... + 395371.

It is an arithmetic number, because the mean of its divisors is an integer number (1186101).

Almost surely, 2^3953665 is an apocalyptic number.

It is an amenable number.

3953665 is a deficient number, since it is larger than the sum of its proper divisors (790739).

3953665 is an equidigital number, since it uses as much as digits as its factorization.

3953665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 790738.

The product of its digits is 72900, while the sum is 37.

The square root of 3953665 is about 1988.3825084727. The cubic root of 3953665 is about 158.1247879202.

It can be divided in two parts, 39536 and 65, that added together give a square (39601 = 199²).

The spelling of 3953665 in words is "three million, nine hundred fifty-three thousand, six hundred sixty-five".