20500117 has 4 divisors (see below), whose sum is σ = 22363776. Its totient is φ = 18636460.

The previous prime is 20500097. The next prime is 20500159. The reversal of 20500117 is 71100502.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20500117 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20500117.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20500217) 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, 931813 + ... + 931834.

It is an arithmetic number, because the mean of its divisors is an integer number (5590944).

Almost surely, 2^20500117 is an apocalyptic number.

It is an amenable number.

20500117 is a deficient number, since it is larger than the sum of its proper divisors (1863659).

20500117 is a wasteful number, since it uses less digits than its factorization.

20500117 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1863658.

The product of its (nonzero) digits is 70, while the sum is 16.

The square root of 20500117 is about 4527.7054895388. The cubic root of 20500117 is about 273.6857044083.

Adding to 20500117 its reverse (71100502), we get a palindrome (91600619).

The spelling of 20500117 in words is "twenty million, five hundred thousand, one hundred seventeen".