21213220122 has 24 divisors (see below), whose sum is σ = 45972232020. Its totient is φ = 7069495680.

The previous prime is 21213220117. The next prime is 21213220139. The reversal of 21213220122 is 22102231212.

It can be written as a sum of positive squares in 2 ways, for example, as 20423553921 + 789666201 = 142911^2 + 28101^2 .

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 = 21213220095 and 21213220104.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 47097 + ... + 211292.

Almost surely, 2^21213220122 is an apocalyptic number.

21213220122 is an abundant number, since it is smaller than the sum of its proper divisors (24759011898).

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

21213220122 is a wasteful number, since it uses less digits than its factorization.

21213220122 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 262958 (or 262955 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

Adding to 21213220122 its reverse (22102231212), we get a palindrome (43315451334).

The spelling of 21213220122 in words is "twenty-one billion, two hundred thirteen million, two hundred twenty thousand, one hundred twenty-two".