123131021100221 has 2 divisors, whose sum is σ = 123131021100222. Its totient is φ = 123131021100220.

The previous prime is 123131021100137. The next prime is 123131021100253. The reversal of 123131021100221 is 122001120131321.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 120804828765625 + 2326192334596 = 10991125^2 + 1525186^2 .

It is a cyclic number.

It is not a de Polignac number, because 123131021100221 - 2³⁴ = 123113841231037 is a prime.

It is a super-2 number, since 2×123131021100221² (a number of 29 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 123131021100193 and 123131021100202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (123131023100221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61565510550110 + 61565510550111.

It is an arithmetic number, because the mean of its divisors is an integer number (61565510550111).

Almost surely, 2^{123131021100221} is an apocalyptic number.

It is an amenable number.

123131021100221 is a deficient number, since it is larger than the sum of its proper divisors (1).

123131021100221 is an equidigital number, since it uses as much as digits as its factorization.

123131021100221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 144, while the sum is 20.

Adding to 123131021100221 its reverse (122001120131321), we get a palindrome (245132141231542).

The spelling of 123131021100221 in words is "one hundred twenty-three trillion, one hundred thirty-one billion, twenty-one million, one hundred thousand, two hundred twenty-one".