4003561 has 4 divisors (see below), whose sum is σ = 4012672. Its totient is φ = 3994452.

The previous prime is 4003529. The next prime is 4003577. The reversal of 4003561 is 1653004.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 4003561 - 2⁵ = 4003529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (4003501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3861 + ... + 4786.

It is an arithmetic number, because the mean of its divisors is an integer number (1003168).

Almost surely, 2^4003561 is an apocalyptic number.

It is an amenable number.

4003561 is a deficient number, since it is larger than the sum of its proper divisors (9111).

4003561 is an equidigital number, since it uses as much as digits as its factorization.

4003561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9110.

The product of its (nonzero) digits is 360, while the sum is 19.

The square root of 4003561 is about 2000.8900519519. The cubic root of 4003561 is about 158.7871973512.

Adding to 4003561 its reverse (1653004), we get a palindrome (5656565).

The spelling of 4003561 in words is "four million, three thousand, five hundred sixty-one".