20021120100020 has 144 divisors (see below), whose sum is σ = 48816551965440. Its totient is φ = 6853719730176.

The previous prime is 20021120099989. The next prime is 20021120100031. The reversal of 20021120100020 is 2000102112002.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 20021120099974 and 20021120100010.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3045941 + ... + 7022819.

Almost surely, 2^{20021120100020} is an apocalyptic number.

20021120100020 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 20021120100020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24408275982720).

20021120100020 is an abundant number, since it is smaller than the sum of its proper divisors (28795431865420).

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

20021120100020 is a wasteful number, since it uses less digits than its factorization.

20021120100020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3977002 (or 3976983 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 20021120100020 its reverse (2000102112002), we get a palindrome (22021222212022).

The spelling of 20021120100020 in words is "twenty trillion, twenty-one billion, one hundred twenty million, one hundred thousand, twenty".