102021100020 has 192 divisors, whose sum is σ = 381833625600. Its totient is φ = 22091771520.

The previous prime is 102021100007. The next prime is 102021100021. The reversal of 102021100020 is 20001120201.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 102021099975 and 102021100011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (102021100021) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 638436 + ... + 782075.

It is an arithmetic number, because the mean of its divisors is an integer number (1988716800).

Almost surely, 2^102021100020 is an apocalyptic number.

102021100020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

102021100020 is an abundant number, since it is smaller than the sum of its proper divisors (279812525580).

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

102021100020 is a wasteful number, since it uses less digits than its factorization.

102021100020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1420555 (or 1420547 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 102021100020 its reverse (20001120201), we get a palindrome (122022220221).

The spelling of 102021100020 in words is "one hundred two billion, twenty-one million, one hundred thousand, twenty".