21320461344 has 288 divisors, whose sum is σ = 70560564480. Its totient is φ = 5620253184.

The previous prime is 21320461343. The next prime is 21320461381. The reversal of 21320461344 is 44316402312.

It is not an unprimeable number, because it can be changed into a prime (21320461343) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 10333657 + ... + 10335719.

It is an arithmetic number, because the mean of its divisors is an integer number (245001960).

Almost surely, 2^21320461344 is an apocalyptic number.

21320461344 is a gapful number since it is divisible by the number (24) 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 21320461344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35280282240).

21320461344 is an abundant number, since it is smaller than the sum of its proper divisors (49240103136).

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

21320461344 is a wasteful number, since it uses less digits than its factorization.

21320461344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2129 (or 2088 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 30.

Adding to 21320461344 its reverse (44316402312), we get a palindrome (65636863656).

The spelling of 21320461344 in words is "twenty-one billion, three hundred twenty million, four hundred sixty-one thousand, three hundred forty-four".