18781317 has 12 divisors (see below), whose sum is σ = 28308384. Its totient is φ = 11976360.

The previous prime is 18781313. The next prime is 18781333. The reversal of 18781317 is 71318781.

It is not a de Polignac number, because 18781317 - 2² = 18781313 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18781313) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 45159 + ... + 45572.

It is an arithmetic number, because the mean of its divisors is an integer number (2359032).

Almost surely, 2^18781317 is an apocalyptic number.

It is an amenable number.

18781317 is a deficient number, since it is larger than the sum of its proper divisors (9527067).

18781317 is a wasteful number, since it uses less digits than its factorization.

18781317 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90760 (or 90757 counting only the distinct ones).

The product of its digits is 9408, while the sum is 36.

The square root of 18781317 is about 4333.7416858876. The cubic root of 18781317 is about 265.8124679288.

The spelling of 18781317 in words is "eighteen million, seven hundred eighty-one thousand, three hundred seventeen".