21212211211020 has 192 divisors, whose sum is σ = 70408924185600. Its totient is φ = 5283208719360.

The previous prime is 21212211210959. The next prime is 21212211211031. The reversal of 21212211211020 is 2011211221212.

21212211211020 is a `hidden beast` number, since 212 + 1 + 221 + 1 + 211 + 0 + 20 = 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 = 21212211210984 and 21212211211002.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 7616880 + ... + 10022039.

It is an arithmetic number, because the mean of its divisors is an integer number (366713146800).

Almost surely, 2^{21212211211020} is an apocalyptic number.

21212211211020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21212211211020 is an abundant number, since it is smaller than the sum of its proper divisors (49196712974580).

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

21212211211020 is a wasteful number, since it uses less digits than its factorization.

21212211211020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17639085 (or 17639077 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 21212211211020 its reverse (2011211221212), we get a palindrome (23223422432232).

The spelling of 21212211211020 in words is "twenty-one trillion, two hundred twelve billion, two hundred eleven million, two hundred eleven thousand, twenty".