18386378 has 4 divisors (see below), whose sum is σ = 27579570. Its totient is φ = 9193188.

The previous prime is 18386371. The next prime is 18386399. The reversal of 18386378 is 87368381.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 87368381 = 1229 ⋅71089.

It can be written as a sum of positive squares in only one way, i.e., 16024009 + 2362369 = 4003^2 + 1537^2 .

It is not an unprimeable number, because it can be changed into a prime (18386371) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4596593 + ... + 4596596.

Almost surely, 2^18386378 is an apocalyptic number.

18386378 is a deficient number, since it is larger than the sum of its proper divisors (9193192).

18386378 is an equidigital number, since it uses as much as digits as its factorization.

18386378 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9193191.

The product of its digits is 193536, while the sum is 44.

The square root of 18386378 is about 4287.9340013578. The cubic root of 18386378 is about 263.9360592776.

The spelling of 18386378 in words is "eighteen million, three hundred eighty-six thousand, three hundred seventy-eight".