20315117 has 2 divisors, whose sum is σ = 20315118. Its totient is φ = 20315116.

The previous prime is 20315083. The next prime is 20315129. The reversal of 20315117 is 71151302.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16859236 + 3455881 = 4106^2 + 1859^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20315117 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20315147) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10157558 + 10157559.

It is an arithmetic number, because the mean of its divisors is an integer number (10157559).

Almost surely, 2^20315117 is an apocalyptic number.

It is an amenable number.

20315117 is a deficient number, since it is larger than the sum of its proper divisors (1).

20315117 is an equidigital number, since it uses as much as digits as its factorization.

20315117 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 210, while the sum is 20.

The square root of 20315117 is about 4507.2294150620. The cubic root of 20315117 is about 272.8599379038.

Adding to 20315117 its reverse (71151302), we get a palindrome (91466419).

The spelling of 20315117 in words is "twenty million, three hundred fifteen thousand, one hundred seventeen".