20131117 has 2 divisors, whose sum is σ = 20131118. Its totient is φ = 20131116.

The previous prime is 20131109. The next prime is 20131129. The reversal of 20131117 is 71113102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12574116 + 7557001 = 3546^2 + 2749^2 .

It is a cyclic number.

It is not a de Polignac number, because 20131117 - 2³ = 20131109 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20131117.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20131147) 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 as a sum of consecutive naturals, namely, 10065558 + 10065559.

It is an arithmetic number, because the mean of its divisors is an integer number (10065559).

Almost surely, 2^20131117 is an apocalyptic number.

It is an amenable number.

20131117 is a deficient number, since it is larger than the sum of its proper divisors (1).

20131117 is an equidigital number, since it uses as much as digits as its factorization.

20131117 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 42, while the sum is 16.

The square root of 20131117 is about 4486.7713335984. The cubic root of 20131117 is about 272.0336472577.

Adding to 20131117 its reverse (71113102), we get a palindrome (91244219).

The spelling of 20131117 in words is "twenty million, one hundred thirty-one thousand, one hundred seventeen".