13103821 has 4 divisors (see below), whose sum is σ = 13874652. Its totient is φ = 12332992.

The previous prime is 13103803. The next prime is 13103833. The reversal of 13103821 is 12830131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12830131 = 101 ⋅127031.

It can be written as a sum of positive squares in 2 ways, for example, as 6702921 + 6400900 = 2589^2 + 2530^2 .

It is a cyclic number.

It is not a de Polignac number, because 13103821 - 2⁵ = 13103789 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13103801) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 385390 + ... + 385423.

It is an arithmetic number, because the mean of its divisors is an integer number (3468663).

Almost surely, 2^13103821 is an apocalyptic number.

It is an amenable number.

13103821 is a deficient number, since it is larger than the sum of its proper divisors (770831).

13103821 is an equidigital number, since it uses as much as digits as its factorization.

13103821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 770830.

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 13103821 is about 3619.9200267409. The cubic root of 13103821 is about 235.7577531976.

Adding to 13103821 its reverse (12830131), we get a palindrome (25933952).

It can be divided in two parts, 13103 and 821, that added together give a square (13924 = 118²).

The spelling of 13103821 in words is "thirteen million, one hundred three thousand, eight hundred twenty-one".