20445442181 has 2 divisors, whose sum is σ = 20445442182. Its totient is φ = 20445442180.

The previous prime is 20445442123. The next prime is 20445442189. The reversal of 20445442181 is 18124454402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20401551556 + 43890625 = 142834^2 + 6625^2 .

It is a cyclic number.

It is not a de Polignac number, because 20445442181 - 2¹⁰ = 20445441157 is a prime.

It is a super-2 number, since 2×20445442181² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20445442189) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10222721090 + 10222721091.

It is an arithmetic number, because the mean of its divisors is an integer number (10222721091).

Almost surely, 2^20445442181 is an apocalyptic number.

It is an amenable number.

20445442181 is a deficient number, since it is larger than the sum of its proper divisors (1).

20445442181 is an equidigital number, since it uses as much as digits as its factorization.

20445442181 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 40960, while the sum is 35.

Adding to 20445442181 its reverse (18124454402), we get a palindrome (38569896583).

The spelling of 20445442181 in words is "twenty billion, four hundred forty-five million, four hundred forty-two thousand, one hundred eighty-one".