16559994397 has 2 divisors, whose sum is σ = 16559994398. Its totient is φ = 16559994396.

The previous prime is 16559994391. The next prime is 16559994419. The reversal of 16559994397 is 79349995561.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11812646596 + 4747347801 = 108686^2 + 68901^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16559994397 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16559994391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8279997198 + 8279997199.

It is an arithmetic number, because the mean of its divisors is an integer number (8279997199).

Almost surely, 2^16559994397 is an apocalyptic number.

It is an amenable number.

16559994397 is a deficient number, since it is larger than the sum of its proper divisors (1).

16559994397 is an equidigital number, since it uses as much as digits as its factorization.

16559994397 is an evil number, because the sum of its binary digits is even.

The product of its digits is 82668600, while the sum is 67.

The spelling of 16559994397 in words is "sixteen billion, five hundred fifty-nine million, nine hundred ninety-four thousand, three hundred ninety-seven".