181123425421 has 2 divisors, whose sum is σ = 181123425422. Its totient is φ = 181123425420.

The previous prime is 181123425389. The next prime is 181123425437. The reversal of 181123425421 is 124524321181.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 167619823396 + 13503602025 = 409414^2 + 116205^2 .

It is a cyclic number.

It is not a de Polignac number, because 181123425421 - 2⁵ = 181123425389 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (181123425451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90561712710 + 90561712711.

It is an arithmetic number, because the mean of its divisors is an integer number (90561712711).

Almost surely, 2^181123425421 is an apocalyptic number.

It is an amenable number.

181123425421 is a deficient number, since it is larger than the sum of its proper divisors (1).

181123425421 is an equidigital number, since it uses as much as digits as its factorization.

181123425421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15360, while the sum is 34.

The spelling of 181123425421 in words is "one hundred eighty-one billion, one hundred twenty-three million, four hundred twenty-five thousand, four hundred twenty-one".