21101010001 has 8 divisors (see below), whose sum is σ = 21168973800. Its totient is φ = 21033078528.

The previous prime is 21101009999. The next prime is 21101010013. The reversal of 21101010001 is 10001010112.

It can be written as a sum of positive squares in 4 ways, for example, as 103550976 + 20997459025 = 10176^2 + 144905^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21101010001 - 2¹ = 21101009999 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21101010041) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2650575 + ... + 2658523.

It is an arithmetic number, because the mean of its divisors is an integer number (2646121725).

Almost surely, 2^21101010001 is an apocalyptic number.

It is an amenable number.

21101010001 is a deficient number, since it is larger than the sum of its proper divisors (67963799).

21101010001 is an equidigital number, since it uses as much as digits as its factorization.

21101010001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16163.

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

Adding to 21101010001 its reverse (10001010112), we get a palindrome (31102020113).

The spelling of 21101010001 in words is "twenty-one billion, one hundred one million, ten thousand, one".