21021212311206 has 16 divisors (see below), whose sum is σ = 42042864313200. Its totient is φ = 7006997488608.

The previous prime is 21021212311117. The next prime is 21021212311217. The reversal of 21021212311206 is 60211321212012.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17697301 + ... + 18847728.

It is an arithmetic number, because the mean of its divisors is an integer number (2627679019575).

Almost surely, 2^{21021212311206} is an apocalyptic number.

21021212311206 is an abundant number, since it is smaller than the sum of its proper divisors (21021652001994).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21021212311206 is a wasteful number, since it uses less digits than its factorization.

21021212311206 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36640903.

The product of its (nonzero) digits is 576, while the sum is 24.

Adding to 21021212311206 its reverse (60211321212012), we get a palindrome (81232533523218).

The spelling of 21021212311206 in words is "twenty-one trillion, twenty-one billion, two hundred twelve million, three hundred eleven thousand, two hundred six".