16517378557 has 2 divisors, whose sum is σ = 16517378558. Its totient is φ = 16517378556.

The previous prime is 16517378513. The next prime is 16517378561. The reversal of 16517378557 is 75587371561.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15483820356 + 1033558201 = 124434^2 + 32149^2 .

It is a cyclic number.

It is not a de Polignac number, because 16517378557 - 2¹¹ = 16517376509 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 16517378498 and 16517378507.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16517378587) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8258689278 + 8258689279.

It is an arithmetic number, because the mean of its divisors is an integer number (8258689279).

Almost surely, 2^16517378557 is an apocalyptic number.

It is an amenable number.

16517378557 is a deficient number, since it is larger than the sum of its proper divisors (1).

16517378557 is an equidigital number, since it uses as much as digits as its factorization.

16517378557 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6174000, while the sum is 55.

The spelling of 16517378557 in words is "sixteen billion, five hundred seventeen million, three hundred seventy-eight thousand, five hundred fifty-seven".