2103521 has 6 divisors (see below), whose sum is σ = 2447010. Its totient is φ = 1802976.

The previous prime is 2103503. The next prime is 2103523. The reversal of 2103521 is 1253012.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 1073296 + 1030225 = 1036^2 + 1015^2 .

It is not a de Polignac number, because 2103521 - 2¹⁰ = 2102497 is a prime.

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 = 2103496 and 2103505.

It is not an unprimeable number, because it can be changed into a prime (2103523) 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 5 ways as a sum of consecutive naturals, for example, 21416 + ... + 21513.

It is an arithmetic number, because the mean of its divisors is an integer number (407835).

2^2103521 is an apocalyptic number.

It is an amenable number.

2103521 is a deficient number, since it is larger than the sum of its proper divisors (343489).

2103521 is an equidigital number, since it uses as much as digits as its factorization.

2103521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42943 (or 42936 counting only the distinct ones).

The product of its (nonzero) digits is 60, while the sum is 14.

The square root of 2103521 is about 1450.3520262336. The cubic root of 2103521 is about 128.1294466829.

Adding to 2103521 its reverse (1253012), we get a palindrome (3356533).

The spelling of 2103521 in words is "two million, one hundred three thousand, five hundred twenty-one".