21220121101020 has 24 divisors (see below), whose sum is σ = 59416339083024. Its totient is φ = 5658698960256.

The previous prime is 21220121101001. The next prime is 21220121101037. The reversal of 21220121101020 is 2010112102212.

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 pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 176834342449 + ... + 176834342568.

It is an arithmetic number, because the mean of its divisors is an integer number (2475680795126).

Almost surely, 2^{21220121101020} is an apocalyptic number.

21220121101020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21220121101020 is an abundant number, since it is smaller than the sum of its proper divisors (38196217982004).

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

21220121101020 is a wasteful number, since it uses less digits than its factorization.

21220121101020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 353668685029 (or 353668685027 counting only the distinct ones).

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

Adding to 21220121101020 its reverse (2010112102212), we get a palindrome (23230233203232).

The spelling of 21220121101020 in words is "twenty-one trillion, two hundred twenty billion, one hundred twenty-one million, one hundred one thousand, twenty".