21202100100001 has 4 divisors (see below), whose sum is σ = 21202110065812. Its totient is φ = 21202090134192.

The previous prime is 21202100099969. The next prime is 21202100100011. The reversal of 21202100100001 is 10000100120212.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 13667069610000 + 7535030490001 = 3696900^2 + 2745001^2 .

It is a cyclic number.

It is not a de Polignac number, because 21202100100001 - 2⁵ = 21202100099969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21202100100011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 365346 + ... + 6522091.

It is an arithmetic number, because the mean of its divisors is an integer number (5300527516453).

Almost surely, 2^{21202100100001} is an apocalyptic number.

It is an amenable number.

21202100100001 is a deficient number, since it is larger than the sum of its proper divisors (9965811).

21202100100001 is an equidigital number, since it uses as much as digits as its factorization.

21202100100001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9965810.

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 21202100100001 its reverse (10000100120212), we get a palindrome (31202200220213).

The spelling of 21202100100001 in words is "twenty-one trillion, two hundred two billion, one hundred million, one hundred thousand, one".