21120310220081 has 2 divisors, whose sum is σ = 21120310220082. Its totient is φ = 21120310220080.

The previous prime is 21120310220071. The next prime is 21120310220129. The reversal of 21120310220081 is 18002201302112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11976998208400 + 9143312011681 = 3460780^2 + 3023791^2 .

It is a cyclic number.

It is not a de Polignac number, because 21120310220081 - 2⁶ = 21120310220017 is a prime.

It is a super-2 number, since 2×21120310220081² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21120310220071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560155110040 + 10560155110041.

It is an arithmetic number, because the mean of its divisors is an integer number (10560155110041).

Almost surely, 2^{21120310220081} is an apocalyptic number.

It is an amenable number.

21120310220081 is a deficient number, since it is larger than the sum of its proper divisors (1).

21120310220081 is an equidigital number, since it uses as much as digits as its factorization.

21120310220081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 384, while the sum is 23.

Adding to 21120310220081 its reverse (18002201302112), we get a palindrome (39122511522193).

The spelling of 21120310220081 in words is "twenty-one trillion, one hundred twenty billion, three hundred ten million, two hundred twenty thousand, eighty-one".