21636460044 has 96 divisors (see below), whose sum is σ = 58065100800. Its totient is φ = 6960090240.

The previous prime is 21636460037. The next prime is 21636460051. The reversal of 21636460044 is 44006463612.

21636460044 is a `hidden beast` number, since 2 + 1 + 6 + 3 + 6 + 4 + 600 + 44 = 666.

It is an interprime number because it is at equal distance from previous prime (21636460037) and next prime (21636460051).

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

It is a junction number, because it is equal to n+sod(n) for n = 21636459990 and 21636460008.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1219912 + ... + 1237520.

It is an arithmetic number, because the mean of its divisors is an integer number (604844800).

Almost surely, 2^21636460044 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 21636460044, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29032550400).

21636460044 is an abundant number, since it is smaller than the sum of its proper divisors (36428640756).

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

21636460044 is a wasteful number, since it uses less digits than its factorization.

21636460044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18020 (or 18012 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 36.

The spelling of 21636460044 in words is "twenty-one billion, six hundred thirty-six million, four hundred sixty thousand, forty-four".