27978739 has 4 divisors (see below), whose sum is σ = 27991656. Its totient is φ = 27965824.

The previous prime is 27978733. The next prime is 27978749. The reversal of 27978739 is 93787972.

It is a happy number.

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 27978739 - 2¹⁹ = 27454451 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (27978733) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2329 + ... + 7834.

It is an arithmetic number, because the mean of its divisors is an integer number (6997914).

Almost surely, 2^27978739 is an apocalyptic number.

27978739 is a deficient number, since it is larger than the sum of its proper divisors (12917).

27978739 is a wasteful number, since it uses less digits than its factorization.

27978739 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12916.

The product of its digits is 1333584, while the sum is 52.

The square root of 27978739 is about 5289.4932649546. The cubic root of 27978739 is about 303.5820194901.

The spelling of 27978739 in words is "twenty-seven million, nine hundred seventy-eight thousand, seven hundred thirty-nine".