13123212021221 has 4 divisors (see below), whose sum is σ = 13443290363244. Its totient is φ = 12803133679200.

The previous prime is 13123212021197. The next prime is 13123212021233. The reversal of 13123212021221 is 12212021232131.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7840638412996 + 5282573608225 = 2800114^2 + 2298385^2 .

It is a cyclic number.

It is not a de Polignac number, because 13123212021221 - 2¹⁰ = 13123212020197 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 (13123212020221) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 160039170950 + ... + 160039171031.

It is an arithmetic number, because the mean of its divisors is an integer number (3360822590811).

Almost surely, 2^{13123212021221} is an apocalyptic number.

It is an amenable number.

13123212021221 is a deficient number, since it is larger than the sum of its proper divisors (320078342023).

13123212021221 is an equidigital number, since it uses as much as digits as its factorization.

13123212021221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 320078342022.

The product of its (nonzero) digits is 576, while the sum is 23.

Adding to 13123212021221 its reverse (12212021232131), we get a palindrome (25335233253352).

The spelling of 13123212021221 in words is "thirteen trillion, one hundred twenty-three billion, two hundred twelve million, twenty-one thousand, two hundred twenty-one".