20504117 has 2 divisors, whose sum is σ = 20504118. Its totient is φ = 20504116.

The previous prime is 20504101. The next prime is 20504119. The reversal of 20504117 is 71140502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19280881 + 1223236 = 4391^2 + 1106^2 .

It is a cyclic number.

It is not a de Polignac number, because 20504117 - 2⁴ = 20504101 is a prime.

Together with 20504119, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20504119) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10252058 + 10252059.

It is an arithmetic number, because the mean of its divisors is an integer number (10252059).

Almost surely, 2^20504117 is an apocalyptic number.

It is an amenable number.

20504117 is a deficient number, since it is larger than the sum of its proper divisors (1).

20504117 is an equidigital number, since it uses as much as digits as its factorization.

20504117 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 280, while the sum is 20.

The square root of 20504117 is about 4528.1471928373. The cubic root of 20504117 is about 273.7035038453.

Adding to 20504117 its reverse (71140502), we get a palindrome (91644619).

The spelling of 20504117 in words is "twenty million, five hundred four thousand, one hundred seventeen".