18782117 has 4 divisors (see below), whose sum is σ = 18954540. Its totient is φ = 18609696.

The previous prime is 18782107. The next prime is 18782123. The reversal of 18782117 is 71128781.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 71128781 = 409 ⋅173909.

It can be written as a sum of positive squares in 2 ways, for example, as 5597956 + 13184161 = 2366^2 + 3631^2 .

It is a cyclic number.

It is not a de Polignac number, because 18782117 - 2²⁴ = 2004901 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 (18782107) 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, 86048 + ... + 86265.

It is an arithmetic number, because the mean of its divisors is an integer number (4738635).

Almost surely, 2^18782117 is an apocalyptic number.

It is an amenable number.

18782117 is a deficient number, since it is larger than the sum of its proper divisors (172423).

18782117 is a wasteful number, since it uses less digits than its factorization.

18782117 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172422.

The product of its digits is 6272, while the sum is 35.

The square root of 18782117 is about 4333.8339838992. The cubic root of 18782117 is about 265.8162420155.

The spelling of 18782117 in words is "eighteen million, seven hundred eighty-two thousand, one hundred seventeen".