21202120001 has 2 divisors, whose sum is σ = 21202120002. Its totient is φ = 21202120000.

The previous prime is 21202119997. The next prime is 21202120003. The reversal of 21202120001 is 10002120212.

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., 20938090000 + 264030001 = 144700^2 + 16249^2 .

It is a cyclic number.

It is not a de Polignac number, because 21202120001 - 2² = 21202119997 is a prime.

Together with 21202120003, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21202120003) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10601060000 + 10601060001.

It is an arithmetic number, because the mean of its divisors is an integer number (10601060001).

Almost surely, 2^21202120001 is an apocalyptic number.

It is an amenable number.

21202120001 is a deficient number, since it is larger than the sum of its proper divisors (1).

21202120001 is an equidigital number, since it uses as much as digits as its factorization.

21202120001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 21202120001 its reverse (10002120212), we get a palindrome (31204240213).

The spelling of 21202120001 in words is "twenty-one billion, two hundred two million, one hundred twenty thousand, one".