21636735552 has 168 divisors, whose sum is σ = 64783919200. Its totient is φ = 7159643136.

The previous prime is 21636735539. The next prime is 21636735577. The reversal of 21636735552 is 25553763612.

21636735552 is a `hidden beast` number, since 2 + 1 + 6 + 3 + 67 + 35 + 552 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 21636735498 and 21636735507.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2156724 + ... + 2166732.

Almost surely, 2^21636735552 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 21636735552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32391959600).

21636735552 is an abundant number, since it is smaller than the sum of its proper divisors (43147183648).

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

21636735552 is a wasteful number, since it uses less digits than its factorization.

21636735552 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10175 (or 10153 counting only the distinct ones).

The product of its digits is 1134000, while the sum is 45.

The spelling of 21636735552 in words is "twenty-one billion, six hundred thirty-six million, seven hundred thirty-five thousand, five hundred fifty-two".