21389327280 has 120 divisors (see below), whose sum is σ = 72639815040. Its totient is φ = 5639715840.

The previous prime is 21389327251. The next prime is 21389327329. The reversal of 21389327280 is 8272398312.

21389327280 is a `hidden beast` number, since 213 + 8 + 93 + 272 + 80 = 666.

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 102816 + ... + 230975.

It is an arithmetic number, because the mean of its divisors is an integer number (605331792).

Almost surely, 2^21389327280 is an apocalyptic number.

21389327280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21389327280 is an abundant number, since it is smaller than the sum of its proper divisors (51250487760).

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

21389327280 is a wasteful number, since it uses less digits than its factorization.

21389327280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 333899 (or 333890 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 45.

The spelling of 21389327280 in words is "twenty-one billion, three hundred eighty-nine million, three hundred twenty-seven thousand, two hundred eighty".