18020987 has 8 divisors (see below), whose sum is σ = 19184400. Its totient is φ = 16879104.

The previous prime is 18020971. The next prime is 18020993. The reversal of 18020987 is 78902081.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 18020987 - 2⁴ = 18020971 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18020917) 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, 3638 + ... + 7019.

It is an arithmetic number, because the mean of its divisors is an integer number (2398050).

Almost surely, 2^18020987 is an apocalyptic number.

18020987 is a deficient number, since it is larger than the sum of its proper divisors (1163413).

18020987 is a wasteful number, since it uses less digits than its factorization.

18020987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10765.

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

The square root of 18020987 is about 4245.1133082640. The cubic root of 18020987 is about 262.1759544899.

The spelling of 18020987 in words is "eighteen million, twenty thousand, nine hundred eighty-seven".