21010100110001 has 4 divisors (see below), whose sum is σ = 21010109323812. Its totient is φ = 21010090896192.

The previous prime is 21010100109991. The next prime is 21010100110031. The reversal of 21010100110001 is 10001100101012.

It is a happy number.

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 15195370719376 + 5814729390625 = 3898124^2 + 2411375^2 .

It is a cyclic number.

It is not a de Polignac number, because 21010100110001 - 2¹⁸ = 21010099847857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21010100110031) 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, 1610405 + ... + 6679341.

It is an arithmetic number, because the mean of its divisors is an integer number (5252527330953).

Almost surely, 2^{21010100110001} is an apocalyptic number.

It is an amenable number.

21010100110001 is a deficient number, since it is larger than the sum of its proper divisors (9213811).

21010100110001 is an equidigital number, since it uses as much as digits as its factorization.

21010100110001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9213810.

The product of its (nonzero) digits is 2, while the sum is 8.

Adding to 21010100110001 its reverse (10001100101012), we get a palindrome (31011200211013).

The spelling of 21010100110001 in words is "twenty-one trillion, ten billion, one hundred million, one hundred ten thousand, one".