21012222121001 has 4 divisors (see below), whose sum is σ = 21012306335172. Its totient is φ = 21012137906832.

The previous prime is 21012222120937. The next prime is 21012222121013. The reversal of 21012222121001 is 10012122221012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9200902823401 + 11811319297600 = 3033299^2 + 3436760^2 .

It is a cyclic number.

It is not a de Polignac number, because 21012222121001 - 2⁶ = 21012222120937 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21012222121061) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 41731706 + ... + 42232211.

It is an arithmetic number, because the mean of its divisors is an integer number (5253076583793).

Almost surely, 2^{21012222121001} is an apocalyptic number.

It is an amenable number.

21012222121001 is a deficient number, since it is larger than the sum of its proper divisors (84214171).

21012222121001 is an equidigital number, since it uses as much as digits as its factorization.

21012222121001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84214170.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21012222121001 its reverse (10012122221012), we get a palindrome (31024344342013).

The spelling of 21012222121001 in words is "twenty-one trillion, twelve billion, two hundred twenty-two million, one hundred twenty-one thousand, one".