13121021323021 has 4 divisors (see below), whose sum is σ = 13368587763132. Its totient is φ = 12873454882912.

The previous prime is 13121021323013. The next prime is 13121021323037. The reversal of 13121021323021 is 12032312012131.

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 10067859194121 + 3053162128900 = 3172989^2 + 1747330^2 .

It is a cyclic number.

It is not a de Polignac number, because 13121021323021 - 2³ = 13121021323013 is a prime.

It is a super-2 number, since 2×13121021323021² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 13121021322983 and 13121021323001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13121021323001) 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, 123783219976 + ... + 123783220081.

It is an arithmetic number, because the mean of its divisors is an integer number (3342146940783).

Almost surely, 2^{13121021323021} is an apocalyptic number.

It is an amenable number.

13121021323021 is a deficient number, since it is larger than the sum of its proper divisors (247566440111).

13121021323021 is an equidigital number, since it uses as much as digits as its factorization.

13121021323021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 247566440110.

The product of its (nonzero) digits is 432, while the sum is 22.

Adding to 13121021323021 its reverse (12032312012131), we get a palindrome (25153333335152).

The spelling of 13121021323021 in words is "thirteen trillion, one hundred twenty-one billion, twenty-one million, three hundred twenty-three thousand, twenty-one".