21004343136 has 576 divisors, whose sum is σ = 75898368000. Its totient is φ = 5501986560.

The previous prime is 21004343111. The next prime is 21004343147. The reversal of 21004343136 is 63134340012.

21004343136 is a `hidden beast` number, since 210 + 0 + 434 + 3 + 13 + 6 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 677559441 + ... + 677559471.

It is an arithmetic number, because the mean of its divisors is an integer number (131768000).

Almost surely, 2^21004343136 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 21004343136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37949184000).

21004343136 is an abundant number, since it is smaller than the sum of its proper divisors (54894024864).

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

21004343136 is an equidigital number, since it uses as much as digits as its factorization.

21004343136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125 (or 62 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 27.

Adding to 21004343136 its reverse (63134340012), we get a palindrome (84138683148).

The spelling of 21004343136 in words is "twenty-one billion, four million, three hundred forty-three thousand, one hundred thirty-six".