21708485568 has 896 divisors, whose sum is σ = 86768025600. Its totient is φ = 5150822400.

The previous prime is 21708485509. The next prime is 21708485573. The reversal of 21708485568 is 86558480712.

21708485568 is a `hidden beast` number, since 2 + 1 + 7 + 0 + 84 + 8 + 556 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 78369846 + ... + 78370122.

Almost surely, 2^21708485568 is an apocalyptic number.

21708485568 is a gapful number since it is divisible by the number (28) 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 21708485568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43384012800).

21708485568 is an abundant number, since it is smaller than the sum of its proper divisors (65059540032).

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

21708485568 is a wasteful number, since it uses less digits than its factorization.

21708485568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 366 (or 350 counting only the distinct ones).

The product of its (nonzero) digits is 4300800, while the sum is 54.

The spelling of 21708485568 in words is "twenty-one billion, seven hundred eight million, four hundred eighty-five thousand, five hundred sixty-eight".