4004521 has 4 divisors (see below), whose sum is σ = 4080132. Its totient is φ = 3928912.

The previous prime is 4004513. The next prime is 4004527. The reversal of 4004521 is 1254004.

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 3258025 + 746496 = 1805^2 + 864^2 .

It is a cyclic number.

It is not a de Polignac number, because 4004521 - 2³ = 4004513 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 4004495 and 4004504.

It is not an unprimeable number, because it can be changed into a prime (4004527) 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, 37726 + ... + 37831.

It is an arithmetic number, because the mean of its divisors is an integer number (1020033).

Almost surely, 2^4004521 is an apocalyptic number.

It is an amenable number.

4004521 is a deficient number, since it is larger than the sum of its proper divisors (75611).

4004521 is an equidigital number, since it uses as much as digits as its factorization.

4004521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75610.

The product of its (nonzero) digits is 160, while the sum is 16.

The square root of 4004521 is about 2001.1299308141. The cubic root of 4004521 is about 158.7998880139.

Adding to 4004521 its reverse (1254004), we get a palindrome (5258525).

The spelling of 4004521 in words is "four million, four thousand, five hundred twenty-one".