20101211210081 has 2 divisors, whose sum is σ = 20101211210082. Its totient is φ = 20101211210080.

The previous prime is 20101211210011. The next prime is 20101211210107. The reversal of 20101211210081 is 18001211210102.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14824933299856 + 5276277910225 = 3850316^2 + 2297015^2 .

It is a cyclic number.

It is not a de Polignac number, because 20101211210081 - 2¹⁴ = 20101211193697 is a prime.

It is a super-2 number, since 2×20101211210081² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20101211210011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10050605605040 + 10050605605041.

It is an arithmetic number, because the mean of its divisors is an integer number (10050605605041).

Almost surely, 2^{20101211210081} is an apocalyptic number.

It is an amenable number.

20101211210081 is a deficient number, since it is larger than the sum of its proper divisors (1).

20101211210081 is an equidigital number, since it uses as much as digits as its factorization.

20101211210081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64, while the sum is 20.

Adding to 20101211210081 its reverse (18001211210102), we get a palindrome (38102422420183).

The spelling of 20101211210081 in words is "twenty trillion, one hundred one billion, two hundred eleven million, two hundred ten thousand, eighty-one".