21021301021211 has 4 divisors (see below), whose sum is σ = 21365912513424. Its totient is φ = 20676689529000.

The previous prime is 21021301021177. The next prime is 21021301021219. The reversal of 21021301021211 is 11212010312012.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21021301021211 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21021301021211.

It is not an unprimeable number, because it can be changed into a prime (21021301021219) 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, 172305746015 + ... + 172305746136.

It is an arithmetic number, because the mean of its divisors is an integer number (5341478128356).

Almost surely, 2^{21021301021211} is an apocalyptic number.

21021301021211 is a deficient number, since it is larger than the sum of its proper divisors (344611492213).

21021301021211 is an equidigital number, since it uses as much as digits as its factorization.

21021301021211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 344611492212.

The product of its (nonzero) digits is 48, while the sum is 17.

Adding to 21021301021211 its reverse (11212010312012), we get a palindrome (32233311333223).

The spelling of 21021301021211 in words is "twenty-one trillion, twenty-one billion, three hundred one million, twenty-one thousand, two hundred eleven".