18406939 has 8 divisors (see below), whose sum is σ = 18976320. Its totient is φ = 17845056.

The previous prime is 18406931. The next prime is 18406943. The reversal of 18406939 is 93960481.

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

It is a cyclic number.

It is not a de Polignac number, because 18406939 - 2³ = 18406931 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18406931) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 3327 + ... + 6919.

It is an arithmetic number, because the mean of its divisors is an integer number (2372040).

Almost surely, 2^18406939 is an apocalyptic number.

18406939 is a deficient number, since it is larger than the sum of its proper divisors (569381).

18406939 is a wasteful number, since it uses less digits than its factorization.

18406939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3749.

The product of its (nonzero) digits is 46656, while the sum is 40.

The square root of 18406939 is about 4290.3308730213. The cubic root of 18406939 is about 264.0344068639.

The spelling of 18406939 in words is "eighteen million, four hundred six thousand, nine hundred thirty-nine".