20718077 has 2 divisors, whose sum is σ = 20718078. Its totient is φ = 20718076.

The previous prime is 20718073. The next prime is 20718083. The reversal of 20718077 is 77081702.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19882681 + 835396 = 4459^2 + 914^2 .

It is a cyclic number.

It is not a de Polignac number, because 20718077 - 2² = 20718073 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20718073) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10359038 + 10359039.

It is an arithmetic number, because the mean of its divisors is an integer number (10359039).

Almost surely, 2^20718077 is an apocalyptic number.

It is an amenable number.

20718077 is a deficient number, since it is larger than the sum of its proper divisors (1).

20718077 is an equidigital number, since it uses as much as digits as its factorization.

20718077 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5488, while the sum is 32.

The square root of 20718077 is about 4551.7114363720. The cubic root of 20718077 is about 274.6522414097.

Adding to 20718077 its reverse (77081702), we get a palindrome (97799779).

The spelling of 20718077 in words is "twenty million, seven hundred eighteen thousand, seventy-seven".