13121221 has 8 divisors (see below), whose sum is σ = 13406400. Its totient is φ = 12839232.

The previous prime is 13121219. The next prime is 13121231. The reversal of 13121221 is 12212131.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 13121221 - 2¹ = 13121219 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 (13121231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8680 + ... + 10078.

It is an arithmetic number, because the mean of its divisors is an integer number (1675800).

Almost surely, 2^13121221 is an apocalyptic number.

It is an amenable number.

13121221 is a deficient number, since it is larger than the sum of its proper divisors (285179).

13121221 is a wasteful number, since it uses less digits than its factorization.

13121221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1595.

The product of its digits is 24, while the sum is 13.

The square root of 13121221 is about 3622.3225974504. The cubic root of 13121221 is about 235.8620579023.

Adding to 13121221 its reverse (12212131), we get a palindrome (25333352).

The spelling of 13121221 in words is "thirteen million, one hundred twenty-one thousand, two hundred twenty-one".