20651317 has 2 divisors, whose sum is σ = 20651318. Its totient is φ = 20651316.

The previous prime is 20651303. The next prime is 20651327. The reversal of 20651317 is 71315602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17859076 + 2792241 = 4226^2 + 1671^2 .

It is a cyclic number.

It is not a de Polignac number, because 20651317 - 2¹¹ = 20649269 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20651291 and 20651300.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20651327) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10325658 + 10325659.

It is an arithmetic number, because the mean of its divisors is an integer number (10325659).

Almost surely, 2^20651317 is an apocalyptic number.

It is an amenable number.

20651317 is a deficient number, since it is larger than the sum of its proper divisors (1).

20651317 is an equidigital number, since it uses as much as digits as its factorization.

20651317 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1260, while the sum is 25.

The square root of 20651317 is about 4544.3720138211. The cubic root of 20651317 is about 274.3569193829.

Adding to 20651317 its reverse (71315602), we get a palindrome (91966919).

The spelling of 20651317 in words is "twenty million, six hundred fifty-one thousand, three hundred seventeen".