21043205480 has 128 divisors (see below), whose sum is σ = 53711631360. Its totient is φ = 7350528000.

The previous prime is 21043205459. The next prime is 21043205503. The reversal of 21043205480 is 8450234012.

It is a happy number.

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 31 ways as a sum of consecutive naturals, for example, 1863050 + ... + 1874310.

It is an arithmetic number, because the mean of its divisors is an integer number (419622120).

Almost surely, 2^21043205480 is an apocalyptic number.

21043205480 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 21043205480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26855815680).

21043205480 is an abundant number, since it is smaller than the sum of its proper divisors (32668425880).

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

21043205480 is a wasteful number, since it uses less digits than its factorization.

21043205480 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11451 (or 11447 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 29.

Adding to 21043205480 its reverse (8450234012), we get a palindrome (29493439492).

The spelling of 21043205480 in words is "twenty-one billion, forty-three million, two hundred five thousand, four hundred eighty".