20021101020 has 96 divisors (see below), whose sum is σ = 62508445440. Its totient is φ = 5320054080.

The previous prime is 20021101013. The next prime is 20021101033. The reversal of 20021101020 is 2010112002.

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 = 20021100993 and 20021101011.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 87315 + ... + 218325.

It is an arithmetic number, because the mean of its divisors is an integer number (651129640).

Almost surely, 2^20021101020 is an apocalyptic number.

20021101020 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 20021101020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31254222720).

20021101020 is an abundant number, since it is smaller than the sum of its proper divisors (42487344420).

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

20021101020 is a wasteful number, since it uses less digits than its factorization.

20021101020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131312 (or 131304 counting only the distinct ones).

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

Adding to 20021101020 its reverse (2010112002), we get a palindrome (22031213022).

The spelling of 20021101020 in words is "twenty billion, twenty-one million, one hundred one thousand, twenty".