18840987 has 12 divisors (see below), whose sum is σ = 29688984. Its totient is φ = 11418720.

The previous prime is 18840967. The next prime is 18841019. The reversal of 18840987 is 78904881.

It is not a de Polignac number, because 18840987 - 2¹⁸ = 18578843 is a prime.

It is a super-2 number, since 2×18840987² = 709965582268338, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18840907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 95058 + ... + 95255.

It is an arithmetic number, because the mean of its divisors is an integer number (2474082).

Almost surely, 2^18840987 is an apocalyptic number.

18840987 is a deficient number, since it is larger than the sum of its proper divisors (10847997).

18840987 is a wasteful number, since it uses less digits than its factorization.

18840987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 190330 (or 190327 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 45.

The square root of 18840987 is about 4340.6205777515. The cubic root of 18840987 is about 266.0936740200.

The spelling of 18840987 in words is "eighteen million, eight hundred forty thousand, nine hundred eighty-seven".