4065021 has 6 divisors (see below), whose sum is σ = 5871710. Its totient is φ = 2710008.

The previous prime is 4065013. The next prime is 4065029. The reversal of 4065021 is 1205604.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (4065013) and next prime (4065029).

It can be written as a sum of positive squares in only one way, i.e., 3956121 + 108900 = 1989^2 + 330^2 .

It is not a de Polignac number, because 4065021 - 2³ = 4065013 is a prime.

It is a Duffinian number.

4065021 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 4064985 and 4065003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4065029) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 225826 + ... + 225843.

Almost surely, 2^4065021 is an apocalyptic number.

It is an amenable number.

4065021 is a deficient number, since it is larger than the sum of its proper divisors (1806689).

4065021 is a wasteful number, since it uses less digits than its factorization.

4065021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 451675 (or 451672 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 4065021 is about 2016.1897232156. The cubic root of 4065021 is about 159.5956063765.

The spelling of 4065021 in words is "four million, sixty-five thousand, twenty-one".