21504660880 has 40 divisors (see below), whose sum is σ = 50100257664. Its totient is φ = 8584329600.

The previous prime is 21504660869. The next prime is 21504660889. The reversal of 21504660880 is 8806640512.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is not an unprimeable number, because it can be changed into a prime (21504660889) 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 7 ways as a sum of consecutive naturals, for example, 234456 + ... + 313015.

Almost surely, 2^21504660880 is an apocalyptic number.

21504660880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21504660880 is an abundant number, since it is smaller than the sum of its proper divisors (28595596784).

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

21504660880 is a wasteful number, since it uses less digits than its factorization.

21504660880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 547975 (or 547969 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 40.

The spelling of 21504660880 in words is "twenty-one billion, five hundred four million, six hundred sixty thousand, eight hundred eighty".