21122020212 has 12 divisors (see below), whose sum is σ = 49284713856. Its totient is φ = 7040673400.

The previous prime is 21122020189. The next prime is 21122020219. The reversal of 21122020212 is 21202022112.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×21122020212² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21122020191 and 21122020200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21122020219) 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, 880084164 + ... + 880084187.

It is an arithmetic number, because the mean of its divisors is an integer number (4107059488).

Almost surely, 2^21122020212 is an apocalyptic number.

It is an amenable number.

21122020212 is an abundant number, since it is smaller than the sum of its proper divisors (28162693644).

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

21122020212 is a wasteful number, since it uses less digits than its factorization.

21122020212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1760168358 (or 1760168356 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 21122020212 its reverse (21202022112), we get a palindrome (42324042324).

The spelling of 21122020212 in words is "twenty-one billion, one hundred twenty-two million, twenty thousand, two hundred twelve".