20616517 has 2 divisors, whose sum is σ = 20616518. Its totient is φ = 20616516.

The previous prime is 20616493. The next prime is 20616521. The reversal of 20616517 is 71561602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20304036 + 312481 = 4506^2 + 559^2 .

It is a cyclic number.

It is not a de Polignac number, because 20616517 - 2⁷ = 20616389 is a prime.

It is a super-2 number, since 2×20616517² = 850081546422578, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20616017) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10308258 + 10308259.

It is an arithmetic number, because the mean of its divisors is an integer number (10308259).

Almost surely, 2^20616517 is an apocalyptic number.

It is an amenable number.

20616517 is a deficient number, since it is larger than the sum of its proper divisors (1).

20616517 is an equidigital number, since it uses as much as digits as its factorization.

20616517 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2520, while the sum is 28.

The square root of 20616517 is about 4540.5414875321. The cubic root of 20616517 is about 274.2027243939.

The spelling of 20616517 in words is "twenty million, six hundred sixteen thousand, five hundred seventeen".