21021221100222 has 48 divisors (see below), whose sum is σ = 52462410104832. Its totient is φ = 5958771330960.

The previous prime is 21021221100211. The next prime is 21021221100251. The reversal of 21021221100222 is 22200112212012.

It is a happy number.

21021221100222 is a `hidden beast` number, since 21 + 0 + 212 + 211 + 0 + 0 + 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 = 21021221100195 and 21021221100204.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 656815054 + ... + 656847057.

It is an arithmetic number, because the mean of its divisors is an integer number (1092966877184).

Almost surely, 2^{21021221100222} is an apocalyptic number.

21021221100222 is an abundant number, since it is smaller than the sum of its proper divisors (31441189004610).

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

21021221100222 is a wasteful number, since it uses less digits than its factorization.

21021221100222 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1313662253 (or 1313662250 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21021221100222 its reverse (22200112212012), we get a palindrome (43221333312234).

The spelling of 21021221100222 in words is "twenty-one trillion, twenty-one billion, two hundred twenty-one million, one hundred thousand, two hundred twenty-two".