1021100120020 has 48 divisors (see below), whose sum is σ = 2261221522560. Its totient is φ = 386248431744.

The previous prime is 1021100119999. The next prime is 1021100120023. The reversal of 1021100120020 is 200210011201.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a junction number, because it is equal to n+sod(n) for n = 1021100119979 and 1021100120006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021100120023) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2200464 + ... + 2623783.

It is an arithmetic number, because the mean of its divisors is an integer number (47108781720).

Almost surely, 2^{1021100120020} is an apocalyptic number.

1021100120020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1021100120020 is an abundant number, since it is smaller than the sum of its proper divisors (1240121402540).

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

1021100120020 is a wasteful number, since it uses less digits than its factorization.

1021100120020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4824832 (or 4824830 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 1021100120020 its reverse (200210011201), we get a palindrome (1221310131221).

The spelling of 1021100120020 in words is "one trillion, twenty-one billion, one hundred million, one hundred twenty thousand, twenty".