21002230020 has 96 divisors (see below), whose sum is σ = 59560824960. Its totient is φ = 5529185280.

The previous prime is 21002230019. The next prime is 21002230037. The reversal of 21002230020 is 2003220012.

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 = 21002229978 and 21002230005.

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, 1502584 + ... + 1516496.

It is an arithmetic number, because the mean of its divisors is an integer number (620425260).

Almost surely, 2^21002230020 is an apocalyptic number.

21002230020 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 21002230020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29780412480).

21002230020 is an abundant number, since it is smaller than the sum of its proper divisors (38558594940).

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

21002230020 is a wasteful number, since it uses less digits than its factorization.

21002230020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14245 (or 14243 counting only the distinct ones).

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

Adding to 21002230020 its reverse (2003220012), we get a palindrome (23005450032).

It can be divided in two parts, 210022 and 30020, that added together give a palindrome (240042).

The spelling of 21002230020 in words is "twenty-one billion, two million, two hundred thirty thousand, twenty".