21637986048 has 324 divisors, whose sum is σ = 73155373200. Its totient is φ = 6132768768.

The previous prime is 21637985989. The next prime is 21637986077. The reversal of 21637986048 is 84068973612.

21637986048 is a `hidden beast` number, since 21 + 6 + 3 + 7 + 9 + 8 + 604 + 8 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 21637985985 and 21637986003.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 15466053 + ... + 15467451.

Almost surely, 2^21637986048 is an apocalyptic number.

21637986048 is a gapful number since it is divisible by the number (28) 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 21637986048, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36577686600).

21637986048 is an abundant number, since it is smaller than the sum of its proper divisors (51517387152).

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

21637986048 is a wasteful number, since it uses less digits than its factorization.

21637986048 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1572 (or 1548 counting only the distinct ones).

The product of its (nonzero) digits is 3483648, while the sum is 54.

The spelling of 21637986048 in words is "twenty-one billion, six hundred thirty-seven million, nine hundred eighty-six thousand, forty-eight".