21101000100001 has 2 divisors, whose sum is σ = 21101000100002. Its totient is φ = 21101000100000.

The previous prime is 21101000099999. The next prime is 21101000100013. The reversal of 21101000100001 is 10000100010112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16815371429025 + 4285628670976 = 4100655^2 + 2070176^2 .

It is a cyclic number.

It is not a de Polignac number, because 21101000100001 - 2¹ = 21101000099999 is a prime.

Together with 21101000099999, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21101000100041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10550500050000 + 10550500050001.

It is an arithmetic number, because the mean of its divisors is an integer number (10550500050001).

Almost surely, 2^{21101000100001} is an apocalyptic number.

It is an amenable number.

21101000100001 is a deficient number, since it is larger than the sum of its proper divisors (1).

21101000100001 is an equidigital number, since it uses as much as digits as its factorization.

21101000100001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2, while the sum is 7.

Adding to 21101000100001 its reverse (10000100010112), we get a palindrome (31101100110113).

The spelling of 21101000100001 in words is "twenty-one trillion, one hundred one billion, one hundred thousand, one".