20718936 has 128 divisors (see below), whose sum is σ = 67046400. Its totient is φ = 5806080.

The previous prime is 20718931. The next prime is 20718941. The reversal of 20718936 is 63981702.

It is an interprime number because it is at equal distance from previous prime (20718931) and next prime (20718941).

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

It is a self number, because there is not a number n which added to its sum of digits gives 20718936.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20718931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 107256 + ... + 107448.

It is an arithmetic number, because the mean of its divisors is an integer number (523800).

Almost surely, 2^20718936 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 20718936, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33523200).

20718936 is an abundant number, since it is smaller than the sum of its proper divisors (46327464).

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

20718936 is a wasteful number, since it uses less digits than its factorization.

20718936 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 286 (or 276 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The square root of 20718936 is about 4551.8057955058. The cubic root of 20718936 is about 274.6560371773.

The spelling of 20718936 in words is "twenty million, seven hundred eighteen thousand, nine hundred thirty-six".