21212012120220 has 72 divisors (see below), whose sum is σ = 64475225060064. Its totient is φ = 5644921477248.

The previous prime is 21212012120147. The next prime is 21212012120231. The reversal of 21212012120220 is 2202121021212.

It is a happy number.

21212012120220 is a `hidden beast` number, since 2 + 121 + 201 + 2 + 120 + 220 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 21212012120193 and 21212012120202.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 120902599 + ... + 121077918.

Almost surely, 2^{21212012120220} is an apocalyptic number.

21212012120220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21212012120220 is an abundant number, since it is smaller than the sum of its proper divisors (43263212939844).

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

21212012120220 is a wasteful number, since it uses less digits than its factorization.

21212012120220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 241981019 (or 241981014 counting only the distinct ones).

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

Adding to 21212012120220 its reverse (2202121021212), we get a palindrome (23414133141432).

The spelling of 21212012120220 in words is "twenty-one trillion, two hundred twelve billion, twelve million, one hundred twenty thousand, two hundred twenty".