27978771 has 32 divisors (see below), whose sum is σ = 40624128. Its totient is φ = 17089920.

The previous prime is 27978763. The next prime is 27978779. The reversal of 27978771 is 17787972.

It is an interprime number because it is at equal distance from previous prime (27978763) and next prime (27978779).

It is not a de Polignac number, because 27978771 - 2³ = 27978763 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 27978771.

It is not an unprimeable number, because it can be changed into a prime (27978779) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 161641 + ... + 161813.

It is an arithmetic number, because the mean of its divisors is an integer number (1269504).

Almost surely, 2^27978771 is an apocalyptic number.

27978771 is a deficient number, since it is larger than the sum of its proper divisors (12645357).

27978771 is a wasteful number, since it uses less digits than its factorization.

27978771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 291.

The product of its digits is 345744, while the sum is 48.

The square root of 27978771 is about 5289.4962898182. The cubic root of 27978771 is about 303.5821352282.

The spelling of 27978771 in words is "twenty-seven million, nine hundred seventy-eight thousand, seven hundred seventy-one".