21212120122 has 8 divisors (see below), whose sum is σ = 32915358900. Its totient is φ = 10240333824.

The previous prime is 21212120099. The next prime is 21212120123. The reversal of 21212120122 is 22102121212.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 21010792401 + 201327721 = 144951^2 + 14189^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 21212120096 and 21212120105.

It is not an unprimeable number, because it can be changed into a prime (21212120123) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 182863047 + ... + 182863162.

Almost surely, 2^21212120122 is an apocalyptic number.

21212120122 is a deficient number, since it is larger than the sum of its proper divisors (11703238778).

21212120122 is a wasteful number, since it uses less digits than its factorization.

21212120122 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 365726240.

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

Adding to 21212120122 its reverse (22102121212), we get a palindrome (43314241334).

The spelling of 21212120122 in words is "twenty-one billion, two hundred twelve million, one hundred twenty thousand, one hundred twenty-two".