21211121211210 has 96 divisors (see below), whose sum is σ = 66344559615360. Its totient is φ = 4593084891264.

The previous prime is 21211121211209. The next prime is 21211121211223. The reversal of 21211121211210 is 1211212111212.

It is a happy number.

21211121211210 is a `hidden beast` number, since 2 + 121 + 1 + 121 + 211 + 210 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 885999777 + ... + 886023716.

It is an arithmetic number, because the mean of its divisors is an integer number (691089162660).

Almost surely, 2^{21211121211210} is an apocalyptic number.

21211121211210 is an abundant number, since it is smaller than the sum of its proper divisors (45133438404150).

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

21211121211210 is a wasteful number, since it uses less digits than its factorization.

21211121211210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1772023532 (or 1772023529 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 18.

Adding to 21211121211210 its reverse (1211212111212), we get a palindrome (22422333322422).

The spelling of 21211121211210 in words is "twenty-one trillion, two hundred eleven billion, one hundred twenty-one million, two hundred eleven thousand, two hundred ten".