21304636416 has 704 divisors, whose sum is σ = 76969820160. Its totient is φ = 5693276160.

The previous prime is 21304636373. The next prime is 21304636417. The reversal of 21304636416 is 61463640312.

21304636416 is a `hidden beast` number, since 2 + 1 + 3 + 0 + 4 + 6 + 3 + 641 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21304636417) 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 63 ways as a sum of consecutive naturals, for example, 317979615 + ... + 317979681.

Almost surely, 2^21304636416 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 21304636416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38484910080).

21304636416 is an abundant number, since it is smaller than the sum of its proper divisors (55665183744).

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

21304636416 is a wasteful number, since it uses less digits than its factorization.

21304636416 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 187 (or 163 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 36.

The spelling of 21304636416 in words is "twenty-one billion, three hundred four million, six hundred thirty-six thousand, four hundred sixteen".