21636019674 has 48 divisors (see below), whose sum is σ = 48828675168. Its totient is φ = 7180198992.

The previous prime is 21636019673. The next prime is 21636019703. The reversal of 21636019674 is 47691063612.

21636019674 is a `hidden beast` number, since 2 + 1 + 636 + 0 + 1 + 9 + 6 + 7 + 4 = 666.

It is not an unprimeable number, because it can be changed into a prime (21636019673) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12264 + ... + 208380.

It is an arithmetic number, because the mean of its divisors is an integer number (1017264066).

Almost surely, 2^21636019674 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21636019674, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24414337584).

21636019674 is an abundant number, since it is smaller than the sum of its proper divisors (27192655494).

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

21636019674 is a wasteful number, since it uses less digits than its factorization.

21636019674 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 196361 (or 196349 counting only the distinct ones).

The product of its (nonzero) digits is 326592, while the sum is 45.

The spelling of 21636019674 in words is "twenty-one billion, six hundred thirty-six million, nineteen thousand, six hundred seventy-four".