1003521 has 4 divisors (see below), whose sum is σ = 1338032. Its totient is φ = 669012.

The previous prime is 1003517. The next prime is 1003543. The reversal of 1003521 is 1253001.

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 not a de Polignac number, because 1003521 - 2² = 1003517 is a prime.

It is a D-number.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1003497 and 1003506.

It is not an unprimeable number, because it can be changed into a prime (1003621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 167251 + ... + 167256.

It is an arithmetic number, because the mean of its divisors is an integer number (334508).

It is a Proth number, since it is equal to 245 ⋅ 2¹² + 1 and 245 < 2¹².

2^1003521 is an apocalyptic number.

It is an amenable number.

1003521 is a deficient number, since it is larger than the sum of its proper divisors (334511).

1003521 is an equidigital number, since it uses as much as digits as its factorization.

1003521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 334510.

The product of its (nonzero) digits is 30, while the sum is 12.

The square root of 1003521 is about 1001.7589530421. The cubic root of 1003521 is about 100.1172291861.

Adding to 1003521 its reverse (1253001), we get a palindrome (2256522).

The spelling of 1003521 in words is "one million, three thousand, five hundred twenty-one".