27978999 has 8 divisors (see below), whose sum is σ = 37862400. Its totient is φ = 18374136.

The previous prime is 27978983. The next prime is 27979027. The reversal of 27978999 is 99987972.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 27978999 - 2⁴ = 27978983 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27968999) 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 7 ways as a sum of consecutive naturals, for example, 69399 + ... + 69800.

It is an arithmetic number, because the mean of its divisors is an integer number (4732800).

Almost surely, 2^27978999 is an apocalyptic number.

27978999 is a deficient number, since it is larger than the sum of its proper divisors (9883401).

27978999 is a wasteful number, since it uses less digits than its factorization.

27978999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 139269.

The product of its digits is 5143824, while the sum is 60.

The square root of 27978999 is about 5289.5178419209. The cubic root of 27978999 is about 303.5829598599.

The spelling of 27978999 in words is "twenty-seven million, nine hundred seventy-eight thousand, nine hundred ninety-nine".