21212001121020 has 48 divisors (see below), whose sum is σ = 59497985665440. Its totient is φ = 5646592439296.

The previous prime is 21212001120931. The next prime is 21212001121033. The reversal of 21212001121020 is 2012110021212.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 310627857 + ... + 310696136.

It is an arithmetic number, because the mean of its divisors is an integer number (1239541368030).

Almost surely, 2^{21212001121020} is an apocalyptic number.

21212001121020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21212001121020 is an abundant number, since it is smaller than the sum of its proper divisors (38285984544420).

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

21212001121020 is a wasteful number, since it uses less digits than its factorization.

21212001121020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 621324574 (or 621324572 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21212001121020 its reverse (2012110021212), we get a palindrome (23224111142232).

The spelling of 21212001121020 in words is "twenty-one trillion, two hundred twelve billion, one million, one hundred twenty-one thousand, twenty".