21636936 has 64 divisors (see below), whose sum is σ = 60720000. Its totient is φ = 7138368.

The previous prime is 21636919. The next prime is 21636943. The reversal of 21636936 is 63963612.

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

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

It is a self number, because there is not a number n which added to its sum of digits gives 21636936.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23085 + ... + 24003.

It is an arithmetic number, because the mean of its divisors is an integer number (948750).

Almost surely, 2^21636936 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 21636936, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30360000).

21636936 is an abundant number, since it is smaller than the sum of its proper divisors (39083064).

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

21636936 is a wasteful number, since it uses less digits than its factorization.

21636936 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1043 (or 1033 counting only the distinct ones).

The product of its digits is 34992, while the sum is 36.

The square root of 21636936 is about 4651.5519990644. The cubic root of 21636936 is about 278.6539819576.

The spelling of 21636936 in words is "twenty-one million, six hundred thirty-six thousand, nine hundred thirty-six".