21754171872 has 72 divisors (see below), whose sum is σ = 61972616160. Its totient is φ = 7238592000.

The previous prime is 21754171841. The next prime is 21754171889. The reversal of 21754171872 is 27817145712.

It is a happy number.

21754171872 is a `hidden beast` number, since 21 + 7 + 541 + 7 + 1 + 87 + 2 = 666.

It is a tau number, because it is divible by the number of its divisors (72).

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 97497 + ... + 230247.

It is an arithmetic number, because the mean of its divisors is an integer number (860730780).

Almost surely, 2^21754171872 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 21754171872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30986308080).

21754171872 is an abundant number, since it is smaller than the sum of its proper divisors (40218444288).

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

21754171872 is a wasteful number, since it uses less digits than its factorization.

21754171872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133336 (or 133325 counting only the distinct ones).

The product of its digits is 219520, while the sum is 45.

The spelling of 21754171872 in words is "twenty-one billion, seven hundred fifty-four million, one hundred seventy-one thousand, eight hundred seventy-two".