20123203312081 has 2 divisors, whose sum is σ = 20123203312082. Its totient is φ = 20123203312080.

The previous prime is 20123203312063. The next prime is 20123203312117. The reversal of 20123203312081 is 18021330232102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18238579542225 + 1884623769856 = 4270665^2 + 1372816^2 .

It is a cyclic number.

It is not a de Polignac number, because 20123203312081 - 2²³ = 20123194923473 is a prime.

It is a super-2 number, since 2×20123203312081² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20123203312061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10061601656040 + 10061601656041.

It is an arithmetic number, because the mean of its divisors is an integer number (10061601656041).

Almost surely, 2^{20123203312081} is an apocalyptic number.

It is an amenable number.

20123203312081 is a deficient number, since it is larger than the sum of its proper divisors (1).

20123203312081 is an equidigital number, since it uses as much as digits as its factorization.

20123203312081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456, while the sum is 28.

Adding to 20123203312081 its reverse (18021330232102), we get a palindrome (38144533544183).

The spelling of 20123203312081 in words is "twenty trillion, one hundred twenty-three billion, two hundred three million, three hundred twelve thousand, eighty-one".