1003581 has 6 divisors (see below), whose sum is σ = 1449630. Its totient is φ = 669048.

The previous prime is 1003549. The next prime is 1003589. The reversal of 1003581 is 1853001.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 695556 + 308025 = 834^2 + 555^2 .

It is not a de Polignac number, because 1003581 - 2⁵ = 1003549 is a prime.

It is a super-2 number, since 2×1003581² = 2014349647122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1003589) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 55746 + ... + 55763.

It is an arithmetic number, because the mean of its divisors is an integer number (241605).

2^1003581 is an apocalyptic number.

It is an amenable number.

1003581 is a deficient number, since it is larger than the sum of its proper divisors (446049).

1003581 is a wasteful number, since it uses less digits than its factorization.

1003581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111515 (or 111512 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 18.

The square root of 1003581 is about 1001.7888999185. The cubic root of 1003581 is about 100.1192244654.

Adding to 1003581 its reverse (1853001), we get a palindrome (2856582).

The spelling of 1003581 in words is "one million, three thousand, five hundred eighty-one".