13523021 has 4 divisors (see below), whose sum is σ = 13540992. Its totient is φ = 13505052.

The previous prime is 13523017. The next prime is 13523033. The reversal of 13523021 is 12032531.

13523021 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12032531 = 7 ⋅1718933.

It is a cyclic number.

It is not a de Polignac number, because 13523021 - 2² = 13523017 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13523821) 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, 7805 + ... + 9378.

It is an arithmetic number, because the mean of its divisors is an integer number (3385248).

Almost surely, 2^13523021 is an apocalyptic number.

It is an amenable number.

13523021 is a deficient number, since it is larger than the sum of its proper divisors (17971).

13523021 is an equidigital number, since it uses as much as digits as its factorization.

13523021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17970.

The product of its (nonzero) digits is 180, while the sum is 17.

The square root of 13523021 is about 3677.3660410680. The cubic root of 13523021 is about 238.2454274515.

Adding to 13523021 its reverse (12032531), we get a palindrome (25555552).

The spelling of 13523021 in words is "thirteen million, five hundred twenty-three thousand, twenty-one".