4005641 has 4 divisors (see below), whose sum is σ = 4042500. Its totient is φ = 3968784.

The previous prime is 4005619. The next prime is 4005643. The reversal of 4005641 is 1465004.

It is a happy number.

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 1537600 + 2468041 = 1240^2 + 1571^2 .

It is a cyclic number.

It is not a de Polignac number, because 4005641 - 2¹⁰ = 4004617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (4005643) 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, 18266 + ... + 18483.

It is an arithmetic number, because the mean of its divisors is an integer number (1010625).

Almost surely, 2^4005641 is an apocalyptic number.

It is an amenable number.

4005641 is a deficient number, since it is larger than the sum of its proper divisors (36859).

4005641 is a wasteful number, since it uses less digits than its factorization.

4005641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36858.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 4005641 is about 2001.4097531490. The cubic root of 4005641 is about 158.8146912239.

The spelling of 4005641 in words is "four million, five thousand, six hundred forty-one".