20021320020 has 96 divisors (see below), whose sum is σ = 60517054080. Its totient is φ = 4916482560.

The previous prime is 20021319943. The next prime is 20021320037. The reversal of 20021320020 is 2002312002.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 20021319978 and 20021320005.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 296190 + ... + 357450.

It is an arithmetic number, because the mean of its divisors is an integer number (630385980).

Almost surely, 2^20021320020 is an apocalyptic number.

20021320020 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 20021320020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30258527040).

20021320020 is an abundant number, since it is smaller than the sum of its proper divisors (40495734060).

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

20021320020 is a wasteful number, since it uses less digits than its factorization.

20021320020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61705 (or 61703 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 12.

Adding to 20021320020 its reverse (2002312002), we get a palindrome (22023632022).

The spelling of 20021320020 in words is "twenty billion, twenty-one million, three hundred twenty thousand, twenty".