11212120081 has 2 divisors, whose sum is σ = 11212120082. Its totient is φ = 11212120080.

The previous prime is 11212120079. The next prime is 11212120091. The reversal of 11212120081 is 18002121211.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11154739456 + 57380625 = 105616^2 + 7575^2 .

It is a cyclic number.

It is not a de Polignac number, because 11212120081 - 2¹ = 11212120079 is a prime.

It is a super-2 number, since 2×11212120081² (a number of 21 digits) contains 22 as substring.

Together with 11212120079, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (11212120091) 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, 5606060040 + 5606060041.

It is an arithmetic number, because the mean of its divisors is an integer number (5606060041).

Almost surely, 2^11212120081 is an apocalyptic number.

It is an amenable number.

11212120081 is a deficient number, since it is larger than the sum of its proper divisors (1).

11212120081 is an equidigital number, since it uses as much as digits as its factorization.

11212120081 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 11212120081 its reverse (18002121211), we get a palindrome (29214241292).

The spelling of 11212120081 in words is "eleven billion, two hundred twelve million, one hundred twenty thousand, eighty-one".