21012120222001 has 2 divisors, whose sum is σ = 21012120222002. Its totient is φ = 21012120222000.

The previous prime is 21012120221987. The next prime is 21012120222007. The reversal of 21012120222001 is 10022202121012.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13379061907600 + 7633058314401 = 3657740^2 + 2762799^2 .

It is a cyclic number.

It is not a de Polignac number, because 21012120222001 - 2¹¹ = 21012120219953 is a prime.

It is not a weakly prime, because it can be changed into another prime (21012120222007) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506060111000 + 10506060111001.

It is an arithmetic number, because the mean of its divisors is an integer number (10506060111001).

Almost surely, 2^{21012120222001} is an apocalyptic number.

It is an amenable number.

21012120222001 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012120222001 is an equidigital number, since it uses as much as digits as its factorization.

21012120222001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21012120222001 its reverse (10022202121012), we get a palindrome (31034322343013).

The spelling of 21012120222001 in words is "twenty-one trillion, twelve billion, one hundred twenty million, two hundred twenty-two thousand, one".