21504367680 has 224 divisors, whose sum is σ = 72912061440. Its totient is φ = 5357936640.

The previous prime is 21504367673. The next prime is 21504367697. The reversal of 21504367680 is 8676340512.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 850582 + ... + 875498.

Almost surely, 2^21504367680 is an apocalyptic number.

21504367680 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 21504367680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36456030720).

21504367680 is an abundant number, since it is smaller than the sum of its proper divisors (51407693760).

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

21504367680 is a wasteful number, since it uses less digits than its factorization.

21504367680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24997 (or 24987 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 42.

The spelling of 21504367680 in words is "twenty-one billion, five hundred four million, three hundred sixty-seven thousand, six hundred eighty".