11918978 has 4 divisors (see below), whose sum is σ = 17878470. Its totient is φ = 5959488.

The previous prime is 11918941. The next prime is 11918981. The reversal of 11918978 is 87981911.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 87981911 = 29 ⋅3033859.

It can be written as a sum of positive squares in only one way, i.e., 6932689 + 4986289 = 2633^2 + 2233^2 .

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 2979743 + ... + 2979746.

Almost surely, 2^11918978 is an apocalyptic number.

11918978 is a deficient number, since it is larger than the sum of its proper divisors (5959492).

11918978 is an equidigital number, since it uses as much as digits as its factorization.

11918978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5959491.

The product of its digits is 36288, while the sum is 44.

The square root of 11918978 is about 3452.3872899778. The cubic root of 11918978 is about 228.4264231696.

The spelling of 11918978 in words is "eleven million, nine hundred eighteen thousand, nine hundred seventy-eight".