27907181891 has 4 divisors (see below), whose sum is σ = 27907620000. Its totient is φ = 27906743784.

The previous prime is 27907181879. The next prime is 27907181917. The reversal of 27907181891 is 19818170972.

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

It is a cyclic number.

It is not a de Polignac number, because 27907181891 - 2³⁴ = 10727312707 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (27907184891) 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, 103016 + ... + 257733.

It is an arithmetic number, because the mean of its divisors is an integer number (6976905000).

Almost surely, 2^27907181891 is an apocalyptic number.

27907181891 is a deficient number, since it is larger than the sum of its proper divisors (438109).

27907181891 is an equidigital number, since it uses as much as digits as its factorization.

27907181891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 438108.

The product of its (nonzero) digits is 508032, while the sum is 53.

The spelling of 27907181891 in words is "twenty-seven billion, nine hundred seven million, one hundred eighty-one thousand, eight hundred ninety-one".