27985681669 has 4 divisors (see below), whose sum is σ = 30529834560. Its totient is φ = 25441528780.

The previous prime is 27985681667. The next prime is 27985681679. The reversal of 27985681669 is 96618658972.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 27985681669 - 2¹ = 27985681667 is a prime.

It is a super-2 number, since 2×27985681669² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27985681667) 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, 1272076429 + ... + 1272076450.

It is an arithmetic number, because the mean of its divisors is an integer number (7632458640).

Almost surely, 2^27985681669 is an apocalyptic number.

It is an amenable number.

27985681669 is a deficient number, since it is larger than the sum of its proper divisors (2544152891).

27985681669 is a wasteful number, since it uses less digits than its factorization.

27985681669 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2544152890.

The product of its digits is 78382080, while the sum is 67.

The spelling of 27985681669 in words is "twenty-seven billion, nine hundred eighty-five million, six hundred eighty-one thousand, six hundred sixty-nine".