3995721 has 24 divisors (see below), whose sum is σ = 6115200. Its totient is φ = 2509056.

The previous prime is 3995713. The next prime is 3995729. The reversal of 3995721 is 1275993.

It is an interprime number because it is at equal distance from previous prime (3995713) and next prime (3995729).

It is not a de Polignac number, because 3995721 - 2³ = 3995713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (3995729) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19980 + ... + 20178.

It is an arithmetic number, because the mean of its divisors is an integer number (254800).

Almost surely, 2^3995721 is an apocalyptic number.

It is an amenable number.

3995721 is a deficient number, since it is larger than the sum of its proper divisors (2119479).

3995721 is a wasteful number, since it uses less digits than its factorization.

3995721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 325 (or 322 counting only the distinct ones).

The product of its digits is 17010, while the sum is 36.

The square root of 3995721 is about 1998.9299637556. The cubic root of 3995721 is about 158.6834809249.

The spelling of 3995721 in words is "three million, nine hundred ninety-five thousand, seven hundred twenty-one".