21112100020001 has 4 divisors (see below), whose sum is σ = 21112109211012. Its totient is φ = 21112090828992.

The previous prime is 21112100019977. The next prime is 21112100020003. The reversal of 21112100020001 is 10002000121112.

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 5708869176976 + 15403230843025 = 2389324^2 + 3924695^2 .

It is a cyclic number.

It is not a de Polignac number, because 21112100020001 - 2²² = 21112095825697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21112100020003) 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, 2176205 + ... + 6852741.

It is an arithmetic number, because the mean of its divisors is an integer number (5278027302753).

Almost surely, 2^{21112100020001} is an apocalyptic number.

It is an amenable number.

21112100020001 is a deficient number, since it is larger than the sum of its proper divisors (9191011).

21112100020001 is an equidigital number, since it uses as much as digits as its factorization.

21112100020001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9191010.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 21112100020001 its reverse (10002000121112), we get a palindrome (31114100141113).

It can be divided in two parts, 21112 and 100020001, that multiplied together give a palindrome (2111622261112).

The spelling of 21112100020001 in words is "twenty-one trillion, one hundred twelve billion, one hundred million, twenty thousand, one".