21001200122281 has 2 divisors, whose sum is σ = 21001200122282. Its totient is φ = 21001200122280.

The previous prime is 21001200122267. The next prime is 21001200122303. The reversal of 21001200122281 is 18222100210012.

It is an a-pointer prime, because the next prime (21001200122303) can be obtained adding 21001200122281 to its sum of digits (22).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20526880035600 + 474320086681 = 4530660^2 + 688709^2 .

It is a cyclic number.

It is not a de Polignac number, because 21001200122281 - 2¹¹ = 21001200120233 is a prime.

It is a super-2 number, since 2×21001200122281² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21001200222281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500600061140 + 10500600061141.

It is an arithmetic number, because the mean of its divisors is an integer number (10500600061141).

Almost surely, 2^{21001200122281} is an apocalyptic number.

It is an amenable number.

21001200122281 is a deficient number, since it is larger than the sum of its proper divisors (1).

21001200122281 is an equidigital number, since it uses as much as digits as its factorization.

21001200122281 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 22.

Adding to 21001200122281 its reverse (18222100210012), we get a palindrome (39223300332293).

The spelling of 21001200122281 in words is "twenty-one trillion, one billion, two hundred million, one hundred twenty-two thousand, two hundred eighty-one".