21221220122 has 8 divisors (see below), whose sum is σ = 33704290836. Its totient is φ = 9986456512.

The previous prime is 21221220109. The next prime is 21221220151. The reversal of 21221220122 is 22102212212.

It is a happy number.

21221220122 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 20822778601 + 398441521 = 144301^2 + 19961^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a self number, because there is not a number n which added to its sum of digits gives 21221220122.

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 3 ways as a sum of consecutive naturals, for example, 312076733 + ... + 312076800.

Almost surely, 2^21221220122 is an apocalyptic number.

21221220122 is a deficient number, since it is larger than the sum of its proper divisors (12483070714).

21221220122 is a wasteful number, since it uses less digits than its factorization.

21221220122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 624153552.

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 21221220122 its reverse (22102212212), we get a palindrome (43323432334).

The spelling of 21221220122 in words is "twenty-one billion, two hundred twenty-one million, two hundred twenty thousand, one hundred twenty-two".