21756260448 has 288 divisors, whose sum is σ = 69401588256. Its totient is φ = 6664716288.

The previous prime is 21756260437. The next prime is 21756260453. The reversal of 21756260448 is 84406265712.

21756260448 is a `hidden beast` number, since 2 + 17 + 5 + 626 + 0 + 4 + 4 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 37705536 + ... + 37706112.

It is an arithmetic number, because the mean of its divisors is an integer number (240977737).

Almost surely, 2^21756260448 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 21756260448, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34700794128).

21756260448 is an abundant number, since it is smaller than the sum of its proper divisors (47645327808).

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

21756260448 is a wasteful number, since it uses less digits than its factorization.

21756260448 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 988 (or 968 counting only the distinct ones).

The product of its (nonzero) digits is 645120, while the sum is 45.

The spelling of 21756260448 in words is "twenty-one billion, seven hundred fifty-six million, two hundred sixty thousand, four hundred forty-eight".