21297704832 has 288 divisors, whose sum is σ = 64232606880. Its totient is φ = 6769975296.

The previous prime is 21297704803. The next prime is 21297704843. The reversal of 21297704832 is 23840779212.

21297704832 is a `hidden beast` number, since 2 + 12 + 97 + 70 + 483 + 2 = 666.

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

It is a super-2 number, since 2×21297704832² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 35 ways as a sum of consecutive naturals, for example, 188475208 + ... + 188475320.

It is an arithmetic number, because the mean of its divisors is an integer number (223029885).

Almost surely, 2^21297704832 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 21297704832, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32116303440).

21297704832 is an abundant number, since it is smaller than the sum of its proper divisors (42934902048).

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

21297704832 is a wasteful number, since it uses less digits than its factorization.

21297704832 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 298 (or 224 counting only the distinct ones).

The product of its (nonzero) digits is 338688, while the sum is 45.

The spelling of 21297704832 in words is "twenty-one billion, two hundred ninety-seven million, seven hundred four thousand, eight hundred thirty-two".