16591638361 has 2 divisors, whose sum is σ = 16591638362. Its totient is φ = 16591638360.

The previous prime is 16591638293. The next prime is 16591638379. The reversal of 16591638361 is 16383619561.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11397697600 + 5193940761 = 106760^2 + 72069^2 .

It is a cyclic number.

It is not a de Polignac number, because 16591638361 - 2⁷ = 16591638233 is a prime.

It is not a weakly prime, because it can be changed into another prime (16591632361) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8295819180 + 8295819181.

It is an arithmetic number, because the mean of its divisors is an integer number (8295819181).

Almost surely, 2^16591638361 is an apocalyptic number.

It is an amenable number.

16591638361 is a deficient number, since it is larger than the sum of its proper divisors (1).

16591638361 is an equidigital number, since it uses as much as digits as its factorization.

16591638361 is an evil number, because the sum of its binary digits is even.

The product of its digits is 699840, while the sum is 49.

The spelling of 16591638361 in words is "sixteen billion, five hundred ninety-one million, six hundred thirty-eight thousand, three hundred sixty-one".