21221022222 has 32 divisors (see below), whose sum is σ = 47183018400. Its totient is φ = 7069895424.

The previous prime is 21221022167. The next prime is 21221022239. The reversal of 21221022222 is 22222012212.

21221022222 is a `hidden beast` number, since 212 + 210 + 22 + 222 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 21221022195 and 21221022204.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2013 + ... + 206024.

It is an arithmetic number, because the mean of its divisors is an integer number (1474469325).

Almost surely, 2^21221022222 is an apocalyptic number.

21221022222 is an abundant number, since it is smaller than the sum of its proper divisors (25961996178).

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

21221022222 is a wasteful number, since it uses less digits than its factorization.

21221022222 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 209937 (or 209931 counting only the distinct ones).

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

Adding to 21221022222 its reverse (22222012212), we get a palindrome (43443034434).

It can be divided in two parts, 212210 and 22222, that added together give a palindrome (234432).

The spelling of 21221022222 in words is "twenty-one billion, two hundred twenty-one million, twenty-two thousand, two hundred twenty-two".