21212210120 has 16 divisors (see below), whose sum is σ = 47727472860. Its totient is φ = 8484884032.

The previous prime is 21212210113. The next prime is 21212210209. The reversal of 21212210120 is 2101221212.

It can be written as a sum of positive squares in 2 ways, for example, as 18710409796 + 2501800324 = 136786^2 + 50018^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21212210095 and 21212210104.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 265152587 + ... + 265152666.

Almost surely, 2^21212210120 is an apocalyptic number.

21212210120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21212210120 is an abundant number, since it is smaller than the sum of its proper divisors (26515262740).

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

21212210120 is a wasteful number, since it uses less digits than its factorization.

21212210120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 530305264 (or 530305260 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21212210120 its reverse (2101221212), we get a palindrome (23313431332).

The spelling of 21212210120 in words is "twenty-one billion, two hundred twelve million, two hundred ten thousand, one hundred twenty".