21289595980 has 12 divisors (see below), whose sum is σ = 44708151600. Its totient is φ = 8515838384.

The previous prime is 21289595963. The next prime is 21289595981. The reversal of 21289595980 is 8959598212.

It is not an unprimeable number, because it can be changed into a prime (21289595981) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 532239880 + ... + 532239919.

It is an arithmetic number, because the mean of its divisors is an integer number (3725679300).

Almost surely, 2^21289595980 is an apocalyptic number.

21289595980 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21289595980 is an abundant number, since it is smaller than the sum of its proper divisors (23418555620).

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

21289595980 is a wasteful number, since it uses less digits than its factorization.

21289595980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1064479808 (or 1064479806 counting only the distinct ones).

The product of its (nonzero) digits is 4665600, while the sum is 58.

The spelling of 21289595980 in words is "twenty-one billion, two hundred eighty-nine million, five hundred ninety-five thousand, nine hundred eighty".