27808641697 has 4 divisors (see below), whose sum is σ = 27810106516. Its totient is φ = 27807176880.

The previous prime is 27808641659. The next prime is 27808641713. The reversal of 27808641697 is 79614680872.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 11084720656 + 16723921041 = 105284^2 + 129321^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-27808641697 is a prime.

It is a super-3 number, since 3×27808641697³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (27808641607) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 703554 + ... + 742027.

It is an arithmetic number, because the mean of its divisors is an integer number (6952526629).

Almost surely, 2^27808641697 is an apocalyptic number.

It is an amenable number.

27808641697 is a deficient number, since it is larger than the sum of its proper divisors (1464819).

27808641697 is a wasteful number, since it uses less digits than its factorization.

27808641697 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1464818.

The product of its (nonzero) digits is 8128512, while the sum is 58.

The spelling of 27808641697 in words is "twenty-seven billion, eight hundred eight million, six hundred forty-one thousand, six hundred ninety-seven".