21211000022081 has 2 divisors, whose sum is σ = 21211000022082. Its totient is φ = 21211000022080.

The previous prime is 21211000022063. The next prime is 21211000022119. The reversal of 21211000022081 is 18022000011212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18957446620225 + 2253553401856 = 4354015^2 + 1501184^2 .

It is a cyclic number.

It is not a de Polignac number, because 21211000022081 - 2¹⁴ = 21211000005697 is a prime.

It is a super-2 number, since 2×21211000022081² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21211000022011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605500011040 + 10605500011041.

It is an arithmetic number, because the mean of its divisors is an integer number (10605500011041).

Almost surely, 2^{21211000022081} is an apocalyptic number.

It is an amenable number.

21211000022081 is a deficient number, since it is larger than the sum of its proper divisors (1).

21211000022081 is an equidigital number, since it uses as much as digits as its factorization.

21211000022081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 128, while the sum is 20.

Adding to 21211000022081 its reverse (18022000011212), we get a palindrome (39233000033293).

The spelling of 21211000022081 in words is "twenty-one trillion, two hundred eleven billion, twenty-two thousand, eighty-one".