21012101200020 has 384 divisors, whose sum is σ = 68722086988800. Its totient is φ = 4697964085248.

The previous prime is 21012101200007. The next prime is 21012101200033. The reversal of 21012101200020 is 2000210121012.

It is an interprime number because it is at equal distance from previous prime (21012101200007) and next prime (21012101200033).

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 = 21012101199969 and 21012101200005.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 6758474226 + ... + 6758477334.

It is an arithmetic number, because the mean of its divisors is an integer number (178963768200).

Almost surely, 2^{21012101200020} is an apocalyptic number.

21012101200020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21012101200020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34361043494400).

21012101200020 is an abundant number, since it is smaller than the sum of its proper divisors (47709985788780).

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

21012101200020 is a wasteful number, since it uses less digits than its factorization.

21012101200020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4947 (or 4945 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21012101200020 its reverse (2000210121012), we get a palindrome (23012311321032).

The spelling of 21012101200020 in words is "twenty-one trillion, twelve billion, one hundred one million, two hundred thousand, twenty".