18420394 has 8 divisors (see below), whose sum is σ = 28583460. Its totient is φ = 8892576.

The previous prime is 18420379. The next prime is 18420407. The reversal of 18420394 is 49302481.

It can be written as a sum of positive squares in 2 ways, for example, as 18378369 + 42025 = 4287^2 + 205^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 158739 + ... + 158854.

Almost surely, 2^18420394 is an apocalyptic number.

18420394 is a deficient number, since it is larger than the sum of its proper divisors (10163066).

18420394 is a wasteful number, since it uses less digits than its factorization.

18420394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 317624.

The product of its (nonzero) digits is 6912, while the sum is 31.

The square root of 18420394 is about 4291.8986474520. The cubic root of 18420394 is about 264.0987253198.

The spelling of 18420394 in words is "eighteen million, four hundred twenty thousand, three hundred ninety-four".