20985017 has 2 divisors, whose sum is σ = 20985018. Its totient is φ = 20985016.

The previous prime is 20985001. The next prime is 20985049. The reversal of 20985017 is 71058902.

It is an a-pointer prime, because the next prime (20985049) can be obtained adding 20985017 to its sum of digits (32).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14167696 + 6817321 = 3764^2 + 2611^2 .

It is a cyclic number.

It is not a de Polignac number, because 20985017 - 2⁴ = 20985001 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20985617) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10492508 + 10492509.

It is an arithmetic number, because the mean of its divisors is an integer number (10492509).

Almost surely, 2^20985017 is an apocalyptic number.

It is an amenable number.

20985017 is a deficient number, since it is larger than the sum of its proper divisors (1).

20985017 is an equidigital number, since it uses as much as digits as its factorization.

20985017 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5040, while the sum is 32.

The square root of 20985017 is about 4580.9406239330. The cubic root of 20985017 is about 275.8267878035.

The spelling of 20985017 in words is "twenty million, nine hundred eighty-five thousand, seventeen".