18816317 has 4 divisors (see below), whose sum is σ = 20263740. Its totient is φ = 17368896.

The previous prime is 18816311. The next prime is 18816341. The reversal of 18816317 is 71361881.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 71361881 = 881 ⋅81001.

It can be written as a sum of positive squares in 2 ways, for example, as 3363556 + 15452761 = 1834^2 + 3931^2 .

It is a cyclic number.

It is not a de Polignac number, because 18816317 - 2¹² = 18812221 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 (18816311) 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, 723692 + ... + 723717.

It is an arithmetic number, because the mean of its divisors is an integer number (5065935).

Almost surely, 2^18816317 is an apocalyptic number.

It is an amenable number.

18816317 is a deficient number, since it is larger than the sum of its proper divisors (1447423).

18816317 is a wasteful number, since it uses less digits than its factorization.

18816317 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1447422.

The product of its digits is 8064, while the sum is 35.

The square root of 18816317 is about 4337.7778873520. Note that the first 3 decimals coincide. The cubic root of 18816317 is about 265.9774841024.

The spelling of 18816317 in words is "eighteen million, eight hundred sixteen thousand, three hundred seventeen".