13212121 has 8 divisors (see below), whose sum is σ = 14256704. Its totient is φ = 12171600.

The previous prime is 13212109. The next prime is 13212131. The reversal of 13212121 is 12121231.

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 13212121 - 2⁷ = 13211993 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13212131) 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 7 ways as a sum of consecutive naturals, for example, 12046 + ... + 13096.

It is an arithmetic number, because the mean of its divisors is an integer number (1782088).

Almost surely, 2^13212121 is an apocalyptic number.

It is an amenable number.

13212121 is a deficient number, since it is larger than the sum of its proper divisors (1044583).

13212121 is a wasteful number, since it uses less digits than its factorization.

13212121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2031.

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

The square root of 13212121 is about 3634.8481398815. The cubic root of 13212121 is about 236.4054661982.

Adding to 13212121 its reverse (12121231), we get a palindrome (25333352).

The spelling of 13212121 in words is "thirteen million, two hundred twelve thousand, one hundred twenty-one".