21010002100001 has 4 divisors (see below), whose sum is σ = 21010013722500. Its totient is φ = 21009990477504.

The previous prime is 21010002099953. The next prime is 21010002100013. The reversal of 21010002100001 is 10000120001012.

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 12560283314401 + 8449718785600 = 3544049^2 + 2906840^2 .

It is a cyclic number.

It is not a de Polignac number, because 21010002100001 - 2²⁶ = 21009934991137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21010002400001) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2452676 + ... + 6930773.

It is an arithmetic number, because the mean of its divisors is an integer number (5252503430625).

Almost surely, 2^{21010002100001} is an apocalyptic number.

It is an amenable number.

21010002100001 is a deficient number, since it is larger than the sum of its proper divisors (11622499).

21010002100001 is an equidigital number, since it uses as much as digits as its factorization.

21010002100001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11622498.

The product of its (nonzero) digits is 4, while the sum is 8.

Adding to 21010002100001 its reverse (10000120001012), we get a palindrome (31010122101013).

The spelling of 21010002100001 in words is "twenty-one trillion, ten billion, two million, one hundred thousand, one".