13021321 has 4 divisors (see below), whose sum is σ = 13093444. Its totient is φ = 12949200.

The previous prime is 13021277. The next prime is 13021331. The reversal of 13021321 is 12312031.

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 876096 + 12145225 = 936^2 + 3485^2 .

It is a cyclic number.

It is not a de Polignac number, because 13021321 - 2⁹ = 13020809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13021331) 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, 35790 + ... + 36151.

It is an arithmetic number, because the mean of its divisors is an integer number (3273361).

Almost surely, 2^13021321 is an apocalyptic number.

It is an amenable number.

13021321 is a deficient number, since it is larger than the sum of its proper divisors (72123).

13021321 is an equidigital number, since it uses as much as digits as its factorization.

13021321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72122.

The product of its (nonzero) digits is 36, while the sum is 13.

The square root of 13021321 is about 3608.5067548780. The cubic root of 13021321 is about 235.2619442198.

Adding to 13021321 its reverse (12312031), we get a palindrome (25333352).

The spelling of 13021321 in words is "thirteen million, twenty-one thousand, three hundred twenty-one".