21740617728 has 160 divisors (see below), whose sum is σ = 64960389120. Its totient is φ = 7245987840.

The previous prime is 21740617697. The next prime is 21740617771. The reversal of 21740617728 is 82771604712.

21740617728 is a `hidden beast` number, since 2 + 1 + 7 + 4 + 0 + 617 + 7 + 28 = 666.

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 9 ways as a sum of consecutive naturals, for example, 2650113 + ... + 2658303.

It is an arithmetic number, because the mean of its divisors is an integer number (406002432).

Almost surely, 2^21740617728 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 21740617728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32480194560).

21740617728 is an abundant number, since it is smaller than the sum of its proper divisors (43219771392).

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

21740617728 is an frugal number, since it uses more digits than its factorization.

21740617728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8233 (or 8196 counting only the distinct ones).

The product of its (nonzero) digits is 263424, while the sum is 45.

The spelling of 21740617728 in words is "twenty-one billion, seven hundred forty million, six hundred seventeen thousand, seven hundred twenty-eight".