20201917 has 2 divisors, whose sum is σ = 20201918. Its totient is φ = 20201916.

The previous prime is 20201911. The next prime is 20201939. The reversal of 20201917 is 71910202.

It is an a-pointer prime, because the next prime (20201939) can be obtained adding 20201917 to its sum of digits (22).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18096516 + 2105401 = 4254^2 + 1451^2 .

It is a cyclic number.

It is not a de Polignac number, because 20201917 - 2⁷ = 20201789 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20201911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10100958 + 10100959.

It is an arithmetic number, because the mean of its divisors is an integer number (10100959).

Almost surely, 2^20201917 is an apocalyptic number.

It is an amenable number.

20201917 is a deficient number, since it is larger than the sum of its proper divisors (1).

20201917 is an equidigital number, since it uses as much as digits as its factorization.

20201917 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 252, while the sum is 22.

The square root of 20201917 is about 4494.6542692403. The cubic root of 20201917 is about 272.3521831091.

The spelling of 20201917 in words is "twenty million, two hundred one thousand, nine hundred seventeen".