21317408824 has 8 divisors (see below), whose sum is σ = 39970141560. Its totient is φ = 10658704408.

The previous prime is 21317408813. The next prime is 21317408857. The reversal of 21317408824 is 42880471312.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 1332338044 + ... + 1332338059.

It is an arithmetic number, because the mean of its divisors is an integer number (4996267695).

Almost surely, 2^21317408824 is an apocalyptic number.

It is an amenable number.

21317408824 is a deficient number, since it is larger than the sum of its proper divisors (18652732736).

21317408824 is a wasteful number, since it uses less digits than its factorization.

21317408824 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2664676109 (or 2664676105 counting only the distinct ones).

The product of its (nonzero) digits is 86016, while the sum is 40.

The spelling of 21317408824 in words is "twenty-one billion, three hundred seventeen million, four hundred eight thousand, eight hundred twenty-four".