18406442 has 8 divisors (see below), whose sum is σ = 27883332. Its totient is φ = 9112000.

The previous prime is 18406379. The next prime is 18406471. The reversal of 18406442 is 24460481.

It can be written as a sum of positive squares in 2 ways, for example, as 14600041 + 3806401 = 3821^2 + 1951^2 .

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

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 45359 + ... + 45762.

Almost surely, 2^18406442 is an apocalyptic number.

18406442 is a deficient number, since it is larger than the sum of its proper divisors (9476890).

18406442 is a wasteful number, since it uses less digits than its factorization.

18406442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91224.

The product of its (nonzero) digits is 6144, while the sum is 29.

The square root of 18406442 is about 4290.2729516897. The cubic root of 18406442 is about 264.0320304724.

The spelling of 18406442 in words is "eighteen million, four hundred six thousand, four hundred forty-two".