20021100120181 has 2 divisors, whose sum is σ = 20021100120182. Its totient is φ = 20021100120180.

The previous prime is 20021100120179. The next prime is 20021100120199. The reversal of 20021100120181 is 18102100112002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15364714446225 + 4656385673956 = 3919785^2 + 2157866^2 .

It is a cyclic number.

It is not a de Polignac number, because 20021100120181 - 2¹ = 20021100120179 is a prime.

It is a super-2 number, since 2×20021100120181² (a number of 27 digits) contains 22 as substring.

Together with 20021100120179, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20021100120121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10010550060090 + 10010550060091.

It is an arithmetic number, because the mean of its divisors is an integer number (10010550060091).

Almost surely, 2^{20021100120181} is an apocalyptic number.

It is an amenable number.

20021100120181 is a deficient number, since it is larger than the sum of its proper divisors (1).

20021100120181 is an equidigital number, since it uses as much as digits as its factorization.

20021100120181 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 20021100120181 its reverse (18102100112002), we get a palindrome (38123200232183).

The spelling of 20021100120181 in words is "twenty trillion, twenty-one billion, one hundred million, one hundred twenty thousand, one hundred eighty-one".