18987243 has 8 divisors (see below), whose sum is σ = 27617856. Its totient is φ = 11507400.

The previous prime is 18987239. The next prime is 18987247. The reversal of 18987243 is 34278981.

It is an interprime number because it is at equal distance from previous prime (18987239) and next prime (18987247).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 18987243 - 2² = 18987239 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18987195 and 18987204.

It is not an unprimeable number, because it can be changed into a prime (18987247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 287653 + ... + 287718.

It is an arithmetic number, because the mean of its divisors is an integer number (3452232).

Almost surely, 2^18987243 is an apocalyptic number.

18987243 is a deficient number, since it is larger than the sum of its proper divisors (8630613).

18987243 is a wasteful number, since it uses less digits than its factorization.

18987243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 575385.

The product of its digits is 96768, while the sum is 42.

The square root of 18987243 is about 4357.4353695723. The cubic root of 18987243 is about 266.7804307998.

The spelling of 18987243 in words is "eighteen million, nine hundred eighty-seven thousand, two hundred forty-three".