21021201031211 has 4 divisors (see below), whose sum is σ = 21021875965272. Its totient is φ = 21020526097152.

The previous prime is 21021201031169. The next prime is 21021201031253. The reversal of 21021201031211 is 11213010212012.

It is a happy number.

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

It is an interprime number because it is at equal distance from previous prime (21021201031169) and next prime (21021201031253).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21021201031211 is a prime.

It is a super-2 number, since 2×21021201031211² (a number of 27 digits) contains 22 as substring.

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 21021201031211.

It is not an unprimeable number, because it can be changed into a prime (21021201030211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 337420310 + ... + 337482603.

It is an arithmetic number, because the mean of its divisors is an integer number (5255468991318).

Almost surely, 2^{21021201031211} is an apocalyptic number.

21021201031211 is a deficient number, since it is larger than the sum of its proper divisors (674934061).

21021201031211 is an equidigital number, since it uses as much as digits as its factorization.

21021201031211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 674934060.

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

Adding to 21021201031211 its reverse (11213010212012), we get a palindrome (32234211243223).

The spelling of 21021201031211 in words is "twenty-one trillion, twenty-one billion, two hundred one million, thirty-one thousand, two hundred eleven".