21212112101020 has 48 divisors (see below), whose sum is σ = 47333605017888. Its totient is φ = 7957317294080.

The previous prime is 21212112101017. The next prime is 21212112101023. The reversal of 21212112101020 is 2010121121212.

It is an interprime number because it is at equal distance from previous prime (21212112101017) and next prime (21212112101023).

It is a junction number, because it is equal to n+sod(n) for n = 21212112100985 and 21212112101003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212112101023) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 110916142 + ... + 111107221.

It is an arithmetic number, because the mean of its divisors is an integer number (986116771206).

Almost surely, 2^{21212112101020} is an apocalyptic number.

21212112101020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21212112101020 is an abundant number, since it is smaller than the sum of its proper divisors (26121492916868).

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

21212112101020 is a wasteful number, since it uses less digits than its factorization.

21212112101020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 222023670 (or 222023668 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21212112101020 its reverse (2010121121212), we get a palindrome (23222233222232).

The spelling of 21212112101020 in words is "twenty-one trillion, two hundred twelve billion, one hundred twelve million, one hundred one thousand, twenty".