181426145521 has 2 divisors, whose sum is σ = 181426145522. Its totient is φ = 181426145520.

The previous prime is 181426145501. The next prime is 181426145597. The reversal of 181426145521 is 125541624181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 154379053921 + 27047091600 = 392911^2 + 164460^2 .

It is a cyclic number.

It is not a de Polignac number, because 181426145521 - 2²³ = 181417756913 is a prime.

It is a super-2 number, since 2×181426145521² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (181426145501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90713072760 + 90713072761.

It is an arithmetic number, because the mean of its divisors is an integer number (90713072761).

Almost surely, 2^181426145521 is an apocalyptic number.

It is an amenable number.

181426145521 is a deficient number, since it is larger than the sum of its proper divisors (1).

181426145521 is an equidigital number, since it uses as much as digits as its factorization.

181426145521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 76800, while the sum is 40.

The spelling of 181426145521 in words is "one hundred eighty-one billion, four hundred twenty-six million, one hundred forty-five thousand, five hundred twenty-one".