13215121 has 2 divisors, whose sum is σ = 13215122. Its totient is φ = 13215120.

The previous prime is 13215113. The next prime is 13215151. The reversal of 13215121 is 12151231.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6656400 + 6558721 = 2580^2 + 2561^2 .

It is an emirp because it is prime and its reverse (12151231) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 13215121 - 2³ = 13215113 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 13215095 and 13215104.

It is not a weakly prime, because it can be changed into another prime (13215151) 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 as a sum of consecutive naturals, namely, 6607560 + 6607561.

It is an arithmetic number, because the mean of its divisors is an integer number (6607561).

Almost surely, 2^13215121 is an apocalyptic number.

It is an amenable number.

13215121 is a deficient number, since it is larger than the sum of its proper divisors (1).

13215121 is an equidigital number, since it uses as much as digits as its factorization.

13215121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 60, while the sum is 16.

The square root of 13215121 is about 3635.2607884442. The cubic root of 13215121 is about 236.4233579187.

Adding to 13215121 its reverse (12151231), we get a palindrome (25366352).

The spelling of 13215121 in words is "thirteen million, two hundred fifteen thousand, one hundred twenty-one".