20345117 has 4 divisors (see below), whose sum is σ = 21910140. Its totient is φ = 18780096.

The previous prime is 20345093. The next prime is 20345161. The reversal of 20345117 is 71154302.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 12538681 + 7806436 = 3541^2 + 2794^2 .

It is a cyclic number.

It is not a de Polignac number, because 20345117 - 2²⁴ = 3567901 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20345092 and 20345101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20345167) 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 3 ways as a sum of consecutive naturals, for example, 782492 + ... + 782517.

It is an arithmetic number, because the mean of its divisors is an integer number (5477535).

Almost surely, 2^20345117 is an apocalyptic number.

It is an amenable number.

20345117 is a deficient number, since it is larger than the sum of its proper divisors (1565023).

20345117 is a wasteful number, since it uses less digits than its factorization.

20345117 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1565022.

The product of its (nonzero) digits is 840, while the sum is 23.

The square root of 20345117 is about 4510.5561741320. The cubic root of 20345117 is about 272.9941855846.

Adding to 20345117 its reverse (71154302), we get a palindrome (91499419).

The spelling of 20345117 in words is "twenty million, three hundred forty-five thousand, one hundred seventeen".