21020221320020 has 48 divisors (see below), whose sum is σ = 50334394230288. Its totient is φ = 7304764692480.

The previous prime is 21020221319959. The next prime is 21020221320089. The reversal of 21020221320020 is 2002312202012.

It can be written as a sum of positive squares in 8 ways, for example, as 545502736 + 21019675817284 = 23356^2 + 4584722^2 .

It is a super-3 number, since 3×21020221320020³ (a number of 41 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (17).

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, 2377848671 + ... + 2377857510.

It is an arithmetic number, because the mean of its divisors is an integer number (1048633213131).

Almost surely, 2^{21020221320020} is an apocalyptic number.

21020221320020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21020221320020 is an abundant number, since it is smaller than the sum of its proper divisors (29314172910268).

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

21020221320020 is a wasteful number, since it uses less digits than its factorization.

21020221320020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4755706220 (or 4755706218 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

Adding to 21020221320020 its reverse (2002312202012), we get a palindrome (23022533522032).

The spelling of 21020221320020 in words is "twenty-one trillion, twenty billion, two hundred twenty-one million, three hundred twenty thousand, twenty".