21121022020212 has 36 divisors (see below), whose sum is σ = 53401392706116. Its totient is φ = 7038739451520.

The previous prime is 21121022020207. The next prime is 21121022020261. The reversal of 21121022020212 is 21202022012112.

It is a happy number.

21121022020212 is a `hidden beast` number, since 2 + 1 + 1 + 210 + 220 + 20 + 212 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 5673952584036 + 15447069436176 = 2382006^2 + 3930276^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 66557089 + ... + 66873672.

Almost surely, 2^{21121022020212} is an apocalyptic number.

It is an amenable number.

21121022020212 is an abundant number, since it is smaller than the sum of its proper divisors (32280370685904).

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

21121022020212 is a wasteful number, since it uses less digits than its factorization.

21121022020212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133435168 (or 133435163 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21121022020212 its reverse (21202022012112), we get a palindrome (42323044032324).

It can be divided in two parts, 2112102 and 2020212, that added together give a palindrome (4132314).

The spelling of 21121022020212 in words is "twenty-one trillion, one hundred twenty-one billion, twenty-two million, twenty thousand, two hundred twelve".