21453244320 has 48 divisors (see below), whose sum is σ = 67577721120. Its totient is φ = 5720865024.

The previous prime is 21453244313. The next prime is 21453244331. The reversal of 21453244320 is 2344235412.

It is a tau number, because it is divible by the number of its divisors (48).

It is a super-2 number, since 2×21453244320² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22346650 + ... + 22347609.

It is an arithmetic number, because the mean of its divisors is an integer number (1407869190).

Almost surely, 2^21453244320 is an apocalyptic number.

21453244320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21453244320 is an abundant number, since it is smaller than the sum of its proper divisors (46124476800).

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

21453244320 is a wasteful number, since it uses less digits than its factorization.

21453244320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44694277 (or 44694269 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 30.

Adding to 21453244320 its reverse (2344235412), we get a palindrome (23797479732).

It can be divided in two parts, 214532 and 44320, that added together give a palindrome (258852).

The spelling of 21453244320 in words is "twenty-one billion, four hundred fifty-three million, two hundred forty-four thousand, three hundred twenty".