21012100202020 has 24 divisors (see below), whose sum is σ = 45646976302200. Its totient is φ = 8115018008832.

The previous prime is 21012100202003. The next prime is 21012100202081. The reversal of 21012100202020 is 2020200121012.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 712768193536 + 20299332008484 = 844256^2 + 4505478^2 .

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 18113878905 + ... + 18113880064.

It is an arithmetic number, because the mean of its divisors is an integer number (1901957345925).

Almost surely, 2^{21012100202020} is an apocalyptic number.

21012100202020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21012100202020 is an abundant number, since it is smaller than the sum of its proper divisors (24634876100180).

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

21012100202020 is a wasteful number, since it uses less digits than its factorization.

21012100202020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36227759007 (or 36227759005 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21012100202020 its reverse (2020200121012), we get a palindrome (23032300323032).

The spelling of 21012100202020 in words is "twenty-one trillion, twelve billion, one hundred million, two hundred two thousand, twenty".