21220121020020 has 48 divisors (see below), whose sum is σ = 63986826462720. Its totient is φ = 5223414404736.

The previous prime is 21220121020013. The next prime is 21220121020037. The reversal of 21220121020020 is 2002012102212.

It is a super-2 number, since 2×21220121020020² (a number of 27 digits) contains 22 as substring.

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, 13602640900 + ... + 13602642459.

It is an arithmetic number, because the mean of its divisors is an integer number (1333058884640).

Almost surely, 2^{21220121020020} is an apocalyptic number.

21220121020020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21220121020020 is an abundant number, since it is smaller than the sum of its proper divisors (42766705442700).

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

21220121020020 is a wasteful number, since it uses less digits than its factorization.

21220121020020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27205283384 (or 27205283382 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 21220121020020 its reverse (2002012102212), we get a palindrome (23222133122232).

The spelling of 21220121020020 in words is "twenty-one trillion, two hundred twenty billion, one hundred twenty-one million, twenty thousand, twenty".