21030455320 has 128 divisors (see below), whose sum is σ = 54527616000. Its totient is φ = 7150809600.

The previous prime is 21030455297. The next prime is 21030455321. The reversal of 21030455320 is 2355403012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21030455321) 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 31 ways as a sum of consecutive naturals, for example, 31815790 + ... + 31816450.

It is an arithmetic number, because the mean of its divisors is an integer number (425997000).

Almost surely, 2^21030455320 is an apocalyptic number.

21030455320 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 21030455320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27263808000).

21030455320 is an abundant number, since it is smaller than the sum of its proper divisors (33497160680).

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

21030455320 is a wasteful number, since it uses less digits than its factorization.

21030455320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1449 (or 1445 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 25.

Adding to 21030455320 its reverse (2355403012), we get a palindrome (23385858332).

The spelling of 21030455320 in words is "twenty-one billion, thirty million, four hundred fifty-five thousand, three hundred twenty".