21121212102210 has 96 divisors (see below), whose sum is σ = 61526558014272. Its totient is φ = 4981907514240.

The previous prime is 21121212102187. The next prime is 21121212102241. The reversal of 21121212102210 is 1220121212112.

21121212102210 is a `hidden beast` number, since 2 + 112 + 121 + 210 + 221 + 0 = 666.

It is a super-2 number, since 2×21121212102210² (a number of 27 digits) contains 22 as substring.

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, 288268204 + ... + 288341463.

It is an arithmetic number, because the mean of its divisors is an integer number (640901645982).

Almost surely, 2^{21121212102210} is an apocalyptic number.

21121212102210 is an abundant number, since it is smaller than the sum of its proper divisors (40405345912062).

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

21121212102210 is a wasteful number, since it uses less digits than its factorization.

21121212102210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 576609728 (or 576609725 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 21121212102210 its reverse (1220121212112), we get a palindrome (22341333314322).

The spelling of 21121212102210 in words is "twenty-one trillion, one hundred twenty-one billion, two hundred twelve million, one hundred two thousand, two hundred ten".