13021121 has 4 divisors (see below), whose sum is σ = 13234644. Its totient is φ = 12807600.

The previous prime is 13021117. The next prime is 13021139. The reversal of 13021121 is 12112031.

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 3010225 + 10010896 = 1735^2 + 3164^2 .

It is a cyclic number.

It is not a de Polignac number, because 13021121 - 2² = 13021117 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (13021171) 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, 106670 + ... + 106791.

It is an arithmetic number, because the mean of its divisors is an integer number (3308661).

Almost surely, 2^13021121 is an apocalyptic number.

It is an amenable number.

13021121 is a deficient number, since it is larger than the sum of its proper divisors (213523).

13021121 is an equidigital number, since it uses as much as digits as its factorization.

13021121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213522.

The product of its (nonzero) digits is 12, while the sum is 11.

The square root of 13021121 is about 3608.4790424776. The cubic root of 13021121 is about 235.2607397176.

Adding to 13021121 its reverse (12112031), we get a palindrome (25133152).

The spelling of 13021121 in words is "thirteen million, twenty-one thousand, one hundred twenty-one".