21636421488 has 160 divisors (see below), whose sum is σ = 68762622720. Its totient is φ = 6458538240.

The previous prime is 21636421483. The next prime is 21636421519. The reversal of 21636421488 is 88412463612.

21636421488 is a `hidden beast` number, since 2 + 1 + 636 + 4 + 2 + 1 + 4 + 8 + 8 = 666.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21636421481) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 284406 + ... + 352362.

It is an arithmetic number, because the mean of its divisors is an integer number (429766392).

Almost surely, 2^21636421488 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 21636421488, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34381311360).

21636421488 is an abundant number, since it is smaller than the sum of its proper divisors (47126201232).

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

21636421488 is a wasteful number, since it uses less digits than its factorization.

21636421488 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68052 (or 68040 counting only the distinct ones).

The product of its digits is 442368, while the sum is 45.

The spelling of 21636421488 in words is "twenty-one billion, six hundred thirty-six million, four hundred twenty-one thousand, four hundred eighty-eight".