16638936065 has 8 divisors (see below), whose sum is σ = 21141236520. Its totient is φ = 12528140032.

The previous prime is 16638936037. The next prime is 16638936071. The reversal of 16638936065 is 56063983661.

It is a Cunningham number, because it is equal to 128992²+1.

It can be written as a sum of positive squares in 4 ways, for example, as 5990140816 + 10648795249 = 77396^2 + 103193^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 16638936065 - 2⁸ = 16638935809 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 16638935998 and 16638936016.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 97876010 + ... + 97876179.

It is an arithmetic number, because the mean of its divisors is an integer number (2642654565).

Almost surely, 2^16638936065 is an apocalyptic number.

It is an amenable number.

16638936065 is a deficient number, since it is larger than the sum of its proper divisors (4502300455).

16638936065 is a wasteful number, since it uses less digits than its factorization.

16638936065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 195752211.

The product of its (nonzero) digits is 4199040, while the sum is 53.

The spelling of 16638936065 in words is "sixteen billion, six hundred thirty-eight million, nine hundred thirty-six thousand, sixty-five".