13121033221 has 2 divisors, whose sum is σ = 13121033222. Its totient is φ = 13121033220.

The previous prime is 13121033197. The next prime is 13121033231. The reversal of 13121033221 is 12233012131.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12490521121 + 630512100 = 111761^2 + 25110^2 .

It is a cyclic number.

It is not a de Polignac number, because 13121033221 - 2¹¹ = 13121031173 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13121033231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6560516610 + 6560516611.

It is an arithmetic number, because the mean of its divisors is an integer number (6560516611).

Almost surely, 2^13121033221 is an apocalyptic number.

It is an amenable number.

13121033221 is a deficient number, since it is larger than the sum of its proper divisors (1).

13121033221 is an equidigital number, since it uses as much as digits as its factorization.

13121033221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 13121033221 its reverse (12233012131), we get a palindrome (25354045352).

The spelling of 13121033221 in words is "thirteen billion, one hundred twenty-one million, thirty-three thousand, two hundred twenty-one".