21320011020 has 192 divisors, whose sum is σ = 74594451456. Its totient is φ = 4420120320.

The previous prime is 21320011019. The next prime is 21320011051. The reversal of 21320011020 is 2011002312.

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 = 21320010987 and 21320011005.

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 63 ways as a sum of consecutive naturals, for example, 2134077 + ... + 2144043.

It is an arithmetic number, because the mean of its divisors is an integer number (388512768).

Almost surely, 2^21320011020 is an apocalyptic number.

21320011020 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 21320011020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37297225728).

21320011020 is an abundant number, since it is smaller than the sum of its proper divisors (53274440436).

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

21320011020 is a wasteful number, since it uses less digits than its factorization.

21320011020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10460 (or 10458 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 12.

Adding to 21320011020 its reverse (2011002312), we get a palindrome (23331013332).

The spelling of 21320011020 in words is "twenty-one billion, three hundred twenty million, eleven thousand, twenty".