27805861389 has 4 divisors (see below), whose sum is σ = 37074481856. Its totient is φ = 18537240924.

The previous prime is 27805861387. The next prime is 27805861397. The reversal of 27805861389 is 98316850872.

It is a happy number.

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 not a de Polignac number, because 27805861389 - 2¹ = 27805861387 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27805861387) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4634310229 + ... + 4634310234.

It is an arithmetic number, because the mean of its divisors is an integer number (9268620464).

Almost surely, 2^27805861389 is an apocalyptic number.

It is an amenable number.

27805861389 is a deficient number, since it is larger than the sum of its proper divisors (9268620467).

27805861389 is an equidigital number, since it uses as much as digits as its factorization.

27805861389 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9268620466.

The product of its (nonzero) digits is 5806080, while the sum is 57.

The spelling of 27805861389 in words is "twenty-seven billion, eight hundred five million, eight hundred sixty-one thousand, three hundred eighty-nine".