13121322521 has 2 divisors, whose sum is σ = 13121322522. Its totient is φ = 13121322520.

The previous prime is 13121322481. The next prime is 13121322527. The reversal of 13121322521 is 12522312131.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8222862400 + 4898460121 = 90680^2 + 69989^2 .

It is a cyclic number.

It is not a de Polignac number, because 13121322521 - 2²² = 13117128217 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (13121322527) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6560661260 + 6560661261.

It is an arithmetic number, because the mean of its divisors is an integer number (6560661261).

Almost surely, 2^13121322521 is an apocalyptic number.

It is an amenable number.

13121322521 is a deficient number, since it is larger than the sum of its proper divisors (1).

13121322521 is an equidigital number, since it uses as much as digits as its factorization.

13121322521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 720, while the sum is 23.

Adding to 13121322521 its reverse (12522312131), we get a palindrome (25643634652).

The spelling of 13121322521 in words is "thirteen billion, one hundred twenty-one million, three hundred twenty-two thousand, five hundred twenty-one".