21121220122 has 8 divisors (see below), whose sum is σ = 31684482900. Its totient is φ = 10559725824.

The previous prime is 21121220117. The next prime is 21121220147. The reversal of 21121220122 is 22102212112.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 18335597281 + 2785622841 = 135409^2 + 52779^2 .

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

It is a super-2 number, since 2×21121220122² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21121220096 and 21121220105.

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 411847 + ... + 460282.

Almost surely, 2^21121220122 is an apocalyptic number.

21121220122 is a deficient number, since it is larger than the sum of its proper divisors (10563262778).

21121220122 is a wasteful number, since it uses less digits than its factorization.

21121220122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 884240.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21121220122 its reverse (22102212112), we get a palindrome (43223432234).

The spelling of 21121220122 in words is "twenty-one billion, one hundred twenty-one million, two hundred twenty thousand, one hundred twenty-two".