18406642 has 8 divisors (see below), whose sum is σ = 28022256. Its totient is φ = 9065892.

The previous prime is 18406639. The next prime is 18406667. The reversal of 18406642 is 24660481.

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 (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68548 + ... + 68815.

It is an arithmetic number, because the mean of its divisors is an integer number (3502782).

Almost surely, 2^18406642 is an apocalyptic number.

18406642 is a deficient number, since it is larger than the sum of its proper divisors (9615614).

18406642 is a wasteful number, since it uses less digits than its factorization.

18406642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 137432.

The product of its (nonzero) digits is 9216, while the sum is 31.

The square root of 18406642 is about 4290.2962601667. The cubic root of 18406642 is about 264.0329867719.

The spelling of 18406642 in words is "eighteen million, four hundred six thousand, six hundred forty-two".