21202120012001 has 4 divisors (see below), whose sum is σ = 21202137212100. Its totient is φ = 21202102811904.

The previous prime is 21202120011973. The next prime is 21202120012027. The reversal of 21202120012001 is 10021002120212.

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 912500652001 + 20289619360000 = 955249^2 + 4504400^2 .

It is a cyclic number.

It is not a de Polignac number, because 21202120012001 - 2⁶ = 21202120011937 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21202120012901) 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, 6595256 + ... + 9268313.

It is an arithmetic number, because the mean of its divisors is an integer number (5300534303025).

Almost surely, 2^{21202120012001} is an apocalyptic number.

It is an amenable number.

21202120012001 is a deficient number, since it is larger than the sum of its proper divisors (17200099).

21202120012001 is a wasteful number, since it uses less digits than its factorization.

21202120012001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17200098.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21202120012001 its reverse (10021002120212), we get a palindrome (31223122132213).

The spelling of 21202120012001 in words is "twenty-one trillion, two hundred two billion, one hundred twenty million, twelve thousand, one".