21002122222 has 4 divisors (see below), whose sum is σ = 31503183336. Its totient is φ = 10501061110.

The previous prime is 21002122217. The next prime is 21002122223. The reversal of 21002122222 is 22222120012.

It is a semiprime because it is the product of two primes.

It is a junction number, because it is equal to n+sod(n) for n = 21002122196 and 21002122205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002122223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5250530554 + ... + 5250530557.

It is an arithmetic number, because the mean of its divisors is an integer number (7875795834).

Almost surely, 2^21002122222 is an apocalyptic number.

21002122222 is a deficient number, since it is larger than the sum of its proper divisors (10501061114).

21002122222 is a wasteful number, since it uses less digits than its factorization.

21002122222 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10501061113.

The product of its (nonzero) digits is 128, while the sum is 16.

Adding to 21002122222 its reverse (22222120012), we get a palindrome (43224242234).

The spelling of 21002122222 in words is "twenty-one billion, two million, one hundred twenty-two thousand, two hundred twenty-two".