13663021 has 4 divisors (see below), whose sum is σ = 13742172. Its totient is φ = 13583872.

The previous prime is 13663009. The next prime is 13663037. The reversal of 13663021 is 12036631.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13286025 + 376996 = 3645^2 + 614^2 .

It is a cyclic number.

It is not a de Polignac number, because 13663021 - 2⁷ = 13662893 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 13662983 and 13663001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13663051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39316 + ... + 39661.

It is an arithmetic number, because the mean of its divisors is an integer number (3435543).

Almost surely, 2^13663021 is an apocalyptic number.

It is an amenable number.

13663021 is a deficient number, since it is larger than the sum of its proper divisors (79151).

13663021 is an equidigital number, since it uses as much as digits as its factorization.

13663021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79150.

The product of its (nonzero) digits is 648, while the sum is 22.

The square root of 13663021 is about 3696.3523912095. The cubic root of 13663021 is about 239.0647688936.

Adding to 13663021 its reverse (12036631), we get a palindrome (25699652).

The spelling of 13663021 in words is "thirteen million, six hundred sixty-three thousand, twenty-one".