18406398 has 8 divisors (see below), whose sum is σ = 36812808. Its totient is φ = 6135464.

The previous prime is 18406379. The next prime is 18406471. The reversal of 18406398 is 89360481.

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

18406398 is an admirable number.

It is a congruent number.

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, 1533861 + ... + 1533872.

It is an arithmetic number, because the mean of its divisors is an integer number (4601601).

Almost surely, 2^18406398 is an apocalyptic number.

18406398 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18406398 is a wasteful number, since it uses less digits than its factorization.

18406398 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3067738.

The product of its (nonzero) digits is 41472, while the sum is 39.

The square root of 18406398 is about 4290.2678238077. The cubic root of 18406398 is about 264.0318200856.

The spelling of 18406398 in words is "eighteen million, four hundred six thousand, three hundred ninety-eight".