21210222222 has 48 divisors (see below), whose sum is σ = 54829152720. Its totient is φ = 6060062736.

The previous prime is 21210222211. The next prime is 21210222259. The reversal of 21210222222 is 22222201212.

21210222222 is a `hidden beast` number, since 212 + 10 + 222 + 222 = 666.

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

21210222222 is a modest number, since divided by 222222 gives 21210 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 21210222195 and 21210222204.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4005333 + ... + 4010624.

It is an arithmetic number, because the mean of its divisors is an integer number (1142274015).

Almost surely, 2^21210222222 is an apocalyptic number.

21210222222 is an abundant number, since it is smaller than the sum of its proper divisors (33618930498).

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

21210222222 is a wasteful number, since it uses less digits than its factorization.

21210222222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8015982 (or 8015969 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

Adding to 21210222222 its reverse (22222201212), we get a palindrome (43432423434).

The spelling of 21210222222 in words is "twenty-one billion, two hundred ten million, two hundred twenty-two thousand, two hundred twenty-two".