1003561 has 16 divisors (see below), whose sum is σ = 1209600. Its totient is φ = 822528.

The previous prime is 1003549. The next prime is 1003589. The reversal of 1003561 is 1653001.

It is not a de Polignac number, because 1003561 - 2⁷ = 1003433 is a prime.

It is a Duffinian number.

1003561 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1003361) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4080 + ... + 4318.

It is an arithmetic number, because the mean of its divisors is an integer number (75600).

2^1003561 is an apocalyptic number.

It is an amenable number.

1003561 is a deficient number, since it is larger than the sum of its proper divisors (206039).

1003561 is a wasteful number, since it uses less digits than its factorization.

1003561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 288.

The product of its (nonzero) digits is 90, while the sum is 16.

The square root of 1003561 is about 1001.7789177259. The cubic root of 1003561 is about 100.1185593812.

Adding to 1003561 its reverse (1653001), we get a palindrome (2656562).

The spelling of 1003561 in words is "one million, three thousand, five hundred sixty-one".