20816597 has 2 divisors, whose sum is σ = 20816598. Its totient is φ = 20816596.

The previous prime is 20816569. The next prime is 20816599. The reversal of 20816597 is 79561802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19722481 + 1094116 = 4441^2 + 1046^2 .

It is a cyclic number.

It is not a de Polignac number, because 20816597 - 2¹⁶ = 20751061 is a prime.

Together with 20816599, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20816597.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20816599) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10408298 + 10408299.

It is an arithmetic number, because the mean of its divisors is an integer number (10408299).

Almost surely, 2^20816597 is an apocalyptic number.

It is an amenable number.

20816597 is a deficient number, since it is larger than the sum of its proper divisors (1).

20816597 is an equidigital number, since it uses as much as digits as its factorization.

20816597 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 30240, while the sum is 38.

The square root of 20816597 is about 4562.5209040617. The cubic root of 20816597 is about 275.0869014614.

The spelling of 20816597 in words is "twenty million, eight hundred sixteen thousand, five hundred ninety-seven".