21257760384 has 192 divisors, whose sum is σ = 70066688640. Its totient is φ = 6060054528.

The previous prime is 21257760383. The next prime is 21257760389. The reversal of 21257760384 is 48306775212.

21257760384 is a `hidden beast` number, since 2 + 12 + 577 + 60 + 3 + 8 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (192).

It is not an unprimeable number, because it can be changed into a prime (21257760383) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 3924462 + ... + 3929874.

It is an arithmetic number, because the mean of its divisors is an integer number (364930670).

Almost surely, 2^21257760384 is an apocalyptic number.

21257760384 is a gapful number since it is divisible by the number (24) 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 21257760384, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35033344320).

21257760384 is an abundant number, since it is smaller than the sum of its proper divisors (48808928256).

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

21257760384 is a wasteful number, since it uses less digits than its factorization.

21257760384 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5927 (or 5912 counting only the distinct ones).

The product of its (nonzero) digits is 564480, while the sum is 45.

The spelling of 21257760384 in words is "twenty-one billion, two hundred fifty-seven million, seven hundred sixty thousand, three hundred eighty-four".