212021121281 has 2 divisors, whose sum is σ = 212021121282.
Its totient is φ = 212021121280.
The previous prime is 212021121269. The next prime is 212021121311. The reversal of 212021121281 is 182121120212.
Adding to 212021121281 its reverse (182121120212), we get a palindrome (394142241493).
It is a weak prime.
It can be written as a sum of positive squares in only one way, i.e., 210489181681 + 1531939600 = 458791^2 + 39140^2
It is a cyclic number.
It is a de Polignac number, because none of the positive numbers 2k-212021121281 is a prime.
It is a super-2 number, since 2×2120211212812 (a number of 23 digits) contains 22 as substring.
It is a Sophie Germain prime.
It is a Curzon number.
It is not a weakly prime, because it can be changed into another prime (212021121181) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106010560640 + 106010560641.
It is an arithmetic number, because the mean of its divisors is an integer number (106010560641).
Almost surely, 2212021121281 is an apocalyptic number.
It is an amenable number.
212021121281 is a deficient number, since it is larger than the sum of its proper divisors (1).
212021121281 is an equidigital number, since it uses as much as digits as its factorization.
212021121281 is an evil number, because the sum of its binary digits is even.
The product of its (nonzero) digits is 256, while the sum is 23.
The spelling of 212021121281 in words is "two hundred twelve billion, twenty-one million, one hundred twenty-one thousand, two hundred eighty-one".