21012122212120 has 64 divisors (see below), whose sum is σ = 51673898797920. Its totient is φ = 7642526183424.

The previous prime is 21012122212117. The next prime is 21012122212127. The reversal of 21012122212120 is 2121222121012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012122212127) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 301516857 + ... + 301586536.

Almost surely, 2^{21012122212120} is an apocalyptic number.

21012122212120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21012122212120 is an abundant number, since it is smaller than the sum of its proper divisors (30661776585800).

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

21012122212120 is a wasteful number, since it uses less digits than its factorization.

21012122212120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 603103484 (or 603103480 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 21012122212120 its reverse (2121222121012), we get a palindrome (23133344333132).

The spelling of 21012122212120 in words is "twenty-one trillion, twelve billion, one hundred twenty-two million, two hundred twelve thousand, one hundred twenty".