27891971 has 8 divisors (see below), whose sum is σ = 28924800. Its totient is φ = 26867520.

The previous prime is 27891949. The next prime is 27891973. The reversal of 27891971 is 17919872.

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 27891971 - 2¹⁴ = 27875587 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (27891973) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5135 + ... + 9063.

It is an arithmetic number, because the mean of its divisors is an integer number (3615600).

Almost surely, 2^27891971 is an apocalyptic number.

27891971 is a deficient number, since it is larger than the sum of its proper divisors (1032829).

27891971 is a wasteful number, since it uses less digits than its factorization.

27891971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4189.

The product of its digits is 63504, while the sum is 44.

The square root of 27891971 is about 5281.2849762155. The cubic root of 27891971 is about 303.2678704552.

The spelling of 27891971 in words is "twenty-seven million, eight hundred ninety-one thousand, nine hundred seventy-one".