21000001102020 has 144 divisors (see below), whose sum is σ = 63740741500800. Its totient is φ = 5596420377600.

The previous prime is 21000001102001. The next prime is 21000001102027. The reversal of 21000001102020 is 2020110000012.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 21000001101993 and 21000001102011.

It is not an unprimeable number, because it can be changed into a prime (21000001102027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3256315756 + ... + 3256322204.

It is an arithmetic number, because the mean of its divisors is an integer number (442644038200).

Almost surely, 2^{21000001102020} is an apocalyptic number.

21000001102020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21000001102020 is an abundant number, since it is smaller than the sum of its proper divisors (42740740398780).

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

21000001102020 is a wasteful number, since it uses less digits than its factorization.

21000001102020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15226 (or 15221 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 21000001102020 its reverse (2020110000012), we get a palindrome (23020111102032).

The spelling of 21000001102020 in words is "twenty-one trillion, one million, one hundred two thousand, twenty".