20117844 has 18 divisors (see below), whose sum is σ = 50853530. Its totient is φ = 6705936.

The previous prime is 20117843. The next prime is 20117863. The reversal of 20117844 is 44871102.

It can be written as a sum of positive squares in only one way, i.e., 18818244 + 1299600 = 4338^2 + 1140^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20117843) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 279379 + ... + 279450.

Almost surely, 2^20117844 is an apocalyptic number.

It is an amenable number.

20117844 is an abundant number, since it is smaller than the sum of its proper divisors (30735686).

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

20117844 is a wasteful number, since it uses less digits than its factorization.

20117844 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 558839 (or 558834 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 27.

The square root of 20117844 is about 4485.2919637410. The cubic root of 20117844 is about 271.9738476874.

Adding to 20117844 its reverse (44871102), we get a palindrome (64988946).

The spelling of 20117844 in words is "twenty million, one hundred seventeen thousand, eight hundred forty-four".