21020020002120 has 32 divisors (see below), whose sum is σ = 63060060006720. Its totient is φ = 5605338667200.

The previous prime is 21020020002083. The next prime is 21020020002181. The reversal of 21020020002120 is 2120002002012.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 21020020002096 and 21020020002105.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 87583416556 + ... + 87583416795.

It is an arithmetic number, because the mean of its divisors is an integer number (1970626875210).

Almost surely, 2^{21020020002120} is an apocalyptic number.

21020020002120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21020020002120 is an abundant number, since it is smaller than the sum of its proper divisors (42040040004600).

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

21020020002120 is a wasteful number, since it uses less digits than its factorization.

21020020002120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 175166833365 (or 175166833361 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 12.

Adding to 21020020002120 its reverse (2120002002012), we get a palindrome (23140022004132).

The spelling of 21020020002120 in words is "twenty-one trillion, twenty billion, twenty million, two thousand, one hundred twenty".