21211101001021 has 4 divisors (see below), whose sum is σ = 21215196604000. Its totient is φ = 21207005398044.

The previous prime is 21211101001007. The next prime is 21211101001031. The reversal of 21211101001021 is 12010010111212.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21211101001021 - 2⁷ = 21211101000893 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21211101000992 and 21211101001010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211101001031) 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, 2047793721 + ... + 2047804078.

It is an arithmetic number, because the mean of its divisors is an integer number (5303799151000).

Almost surely, 2^{21211101001021} is an apocalyptic number.

It is an amenable number.

21211101001021 is a deficient number, since it is larger than the sum of its proper divisors (4095602979).

21211101001021 is an equidigital number, since it uses as much as digits as its factorization.

21211101001021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4095602978.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 21211101001021 its reverse (12010010111212), we get a palindrome (33221111112233).

The spelling of 21211101001021 in words is "twenty-one trillion, two hundred eleven billion, one hundred one million, one thousand, twenty-one".