21002221222 has 4 divisors (see below), whose sum is σ = 31503331836. Its totient is φ = 10501110610.

The previous prime is 21002221199. The next prime is 21002221223. The reversal of 21002221222 is 22212220012.

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 = 21002221196 and 21002221205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002221223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5250555304 + ... + 5250555307.

It is an arithmetic number, because the mean of its divisors is an integer number (7875832959).

Almost surely, 2^21002221222 is an apocalyptic number.

21002221222 is a deficient number, since it is larger than the sum of its proper divisors (10501110614).

21002221222 is a wasteful number, since it uses less digits than its factorization.

21002221222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10501110613.

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

Adding to 21002221222 its reverse (22212220012), we get a palindrome (43214441234).

The spelling of 21002221222 in words is "twenty-one billion, two million, two hundred twenty-one thousand, two hundred twenty-two".