27978138 has 48 divisors (see below), whose sum is σ = 62558496. Its totient is φ = 9033120.

The previous prime is 27978121. The next prime is 27978149. The reversal of 27978138 is 83187972.

It is a junction number, because it is equal to n+sod(n) for n = 27978093 and 27978102.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 90981 + ... + 91287.

It is an arithmetic number, because the mean of its divisors is an integer number (1303302).

Almost surely, 2^27978138 is an apocalyptic number.

27978138 is an abundant number, since it is smaller than the sum of its proper divisors (34580358).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

27978138 is a wasteful number, since it uses less digits than its factorization.

27978138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 459 (or 456 counting only the distinct ones).

The product of its digits is 169344, while the sum is 45.

The square root of 27978138 is about 5289.4364539145. The cubic root of 27978138 is about 303.5798457669.

The spelling of 27978138 in words is "twenty-seven million, nine hundred seventy-eight thousand, one hundred thirty-eight".