13523813 has 4 divisors (see below), whose sum is σ = 13531980. Its totient is φ = 13515648.

The previous prime is 13523779. The next prime is 13523821. The reversal of 13523813 is 31832531.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 12124324 + 1399489 = 3482^2 + 1183^2 .

It is a cyclic number.

It is not a de Polignac number, because 13523813 - 2⁸ = 13523557 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13523863) 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, 620 + ... + 5237.

It is an arithmetic number, because the mean of its divisors is an integer number (3382995).

Almost surely, 2^13523813 is an apocalyptic number.

It is an amenable number.

13523813 is a deficient number, since it is larger than the sum of its proper divisors (8167).

13523813 is an equidigital number, since it uses as much as digits as its factorization.

13523813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8166.

The product of its digits is 2160, while the sum is 26.

The square root of 13523813 is about 3677.4737252630. The cubic root of 13523813 is about 238.2500784511.

The spelling of 13523813 in words is "thirteen million, five hundred twenty-three thousand, eight hundred thirteen".