18164939 has 4 divisors (see below), whose sum is σ = 19562256. Its totient is φ = 16767624.

The previous prime is 18164929. The next prime is 18164947. The reversal of 18164939 is 93946181.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18164939 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18164896 and 18164905.

It is not an unprimeable number, because it can be changed into a prime (18164929) 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, 698639 + ... + 698664.

It is an arithmetic number, because the mean of its divisors is an integer number (4890564).

Almost surely, 2^18164939 is an apocalyptic number.

18164939 is a deficient number, since it is larger than the sum of its proper divisors (1397317).

18164939 is a wasteful number, since it uses less digits than its factorization.

18164939 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1397316.

The product of its digits is 46656, while the sum is 41.

The square root of 18164939 is about 4262.0346080247. The cubic root of 18164939 is about 262.8721928129.

The spelling of 18164939 in words is "eighteen million, one hundred sixty-four thousand, nine hundred thirty-nine".