18670399 has 4 divisors (see below), whose sum is σ = 20367720. Its totient is φ = 16973080.

The previous prime is 18670387. The next prime is 18670409. The reversal of 18670399 is 99307681.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 18670399 - 2⁵ = 18670367 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18674399) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 848644 + ... + 848665.

It is an arithmetic number, because the mean of its divisors is an integer number (5091930).

Almost surely, 2^18670399 is an apocalyptic number.

18670399 is a deficient number, since it is larger than the sum of its proper divisors (1697321).

18670399 is a wasteful number, since it uses less digits than its factorization.

18670399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1697320.

The product of its (nonzero) digits is 81648, while the sum is 43.

The square root of 18670399 is about 4320.9257110022. The cubic root of 18670399 is about 265.2881593099.

The spelling of 18670399 in words is "eighteen million, six hundred seventy thousand, three hundred ninety-nine".