21001000212101 has 32 divisors (see below), whose sum is σ = 27369886118400. Its totient is φ = 15637572827136.

The previous prime is 21001000212091. The next prime is 21001000212107. The reversal of 21001000212101 is 10121200010012.

It is a de Polignac number, because none of the positive numbers 2^k-21001000212101 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001000212107) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 20250200 + ... + 21261998.

It is an arithmetic number, because the mean of its divisors is an integer number (855308941200).

Almost surely, 2^{21001000212101} is an apocalyptic number.

It is an amenable number.

21001000212101 is a deficient number, since it is larger than the sum of its proper divisors (6368885906299).

21001000212101 is a wasteful number, since it uses less digits than its factorization.

21001000212101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1025253.

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

Adding to 21001000212101 its reverse (10121200010012), we get a palindrome (31122200222113).

The spelling of 21001000212101 in words is "twenty-one trillion, one billion, two hundred twelve thousand, one hundred one".