18987009 has 8 divisors (see below), whose sum is σ = 25509792. Its totient is φ = 12561120.

The previous prime is 18986999. The next prime is 18987019. The reversal of 18987009 is 90078981.

It is an interprime number because it is at equal distance from previous prime (18986999) and next prime (18987019).

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

It is not a de Polignac number, because 18987009 - 2¹² = 18982913 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18987019) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23764 + ... + 24549.

It is an arithmetic number, because the mean of its divisors is an integer number (3188724).

Almost surely, 2^18987009 is an apocalyptic number.

It is an amenable number.

18987009 is a deficient number, since it is larger than the sum of its proper divisors (6522783).

18987009 is a wasteful number, since it uses less digits than its factorization.

18987009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48447.

The product of its (nonzero) digits is 36288, while the sum is 42.

The square root of 18987009 is about 4357.4085188332. The cubic root of 18987009 is about 266.7793348556.

The spelling of 18987009 in words is "eighteen million, nine hundred eighty-seven thousand, nine".