21020020212020 has 24 divisors (see below), whose sum is σ = 44238633366984. Its totient is φ = 8389609814016.

The previous prime is 21020020212011. The next prime is 21020020212041. The reversal of 21020020212020 is 2021202002012.

It can be written as a sum of positive squares in 4 ways, for example, as 4060152460324 + 16959867751696 = 2014982^2 + 4118236^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21020020211986 and 21020020212004.

It is a congruent number.

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, 1149882557 + ... + 1149900836.

It is an arithmetic number, because the mean of its divisors is an integer number (1843276390291).

Almost surely, 2^{21020020212020} is an apocalyptic number.

21020020212020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21020020212020 is an abundant number, since it is smaller than the sum of its proper divisors (23218613154964).

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

21020020212020 is a wasteful number, since it uses less digits than its factorization.

21020020212020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2299783859 (or 2299783857 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 14.

Adding to 21020020212020 its reverse (2021202002012), we get a palindrome (23041222214032).

The spelling of 21020020212020 in words is "twenty-one trillion, twenty billion, twenty million, two hundred twelve thousand, twenty".