100021200020 has 72 divisors (see below), whose sum is σ = 244657080360. Its totient is φ = 34248130560.

The previous prime is 100021199987. The next prime is 100021200031. The reversal of 100021200020 is 20002120001.

It can be written as a sum of positive squares in 4 ways, for example, as 33620156164 + 66401043856 = 183358^2 + 257684^2 .

It is a junction number, because it is equal to n+sod(n) for n = 100021199980 and 100021200007.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 687260 + ... + 819980.

It is an arithmetic number, because the mean of its divisors is an integer number (3398015005).

Almost surely, 2^100021200020 is an apocalyptic number.

100021200020 is a gapful number since it is divisible by the number (10) 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 100021200020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (122328540180).

100021200020 is an abundant number, since it is smaller than the sum of its proper divisors (144635880340).

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

100021200020 is a wasteful number, since it uses less digits than its factorization.

100021200020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133513 (or 133504 counting only the distinct ones).

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

Adding to 100021200020 its reverse (20002120001), we get a palindrome (120023320021).

The spelling of 100021200020 in words is "one hundred billion, twenty-one million, two hundred thousand, twenty".