21011000320 has 88 divisors (see below), whose sum is σ = 51474746304. Its totient is φ = 8225488896.

The previous prime is 21011000317. The next prime is 21011000321. The reversal of 21011000320 is 2300011012.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a junction number, because it is equal to n+sod(n) for n = 21011000297 and 21011000306.

It is not an unprimeable number, because it can be changed into a prime (21011000321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 196984 + ... + 284296.

Almost surely, 2^21011000320 is an apocalyptic number.

21011000320 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 21011000320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25737373152).

21011000320 is an abundant number, since it is smaller than the sum of its proper divisors (30463745984).

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

21011000320 is an equidigital number, since it uses as much as digits as its factorization.

21011000320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87385 (or 87367 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 10.

Adding to 21011000320 its reverse (2300011012), we get a palindrome (23311011332).

The spelling of 21011000320 in words is "twenty-one billion, eleven million, three hundred twenty", and thus it is an aban number.