21547111968 has 240 divisors, whose sum is σ = 65755388160. Its totient is φ = 6914419200.

The previous prime is 21547111967. The next prime is 21547111981. The reversal of 21547111968 is 86911174512.

21547111968 is a `hidden beast` number, since 2 + 1 + 5 + 471 + 119 + 68 = 666.

It is not an unprimeable number, because it can be changed into a prime (21547111967) 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 39 ways as a sum of consecutive naturals, for example, 18400023 + ... + 18401193.

It is an arithmetic number, because the mean of its divisors is an integer number (273980784).

Almost surely, 2^21547111968 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21547111968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32877694080).

21547111968 is an abundant number, since it is smaller than the sum of its proper divisors (44208276192).

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

21547111968 is a wasteful number, since it uses less digits than its factorization.

21547111968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1453 (or 1436 counting only the distinct ones).

The product of its digits is 120960, while the sum is 45.

The spelling of 21547111968 in words is "twenty-one billion, five hundred forty-seven million, one hundred eleven thousand, nine hundred sixty-eight".