18879987 has 16 divisors (see below), whose sum is σ = 30021120. Its totient is φ = 10319232.

The previous prime is 18879919. The next prime is 18880007. The reversal of 18879987 is 78997881.

It is not a de Polignac number, because 18879987 - 2⁷ = 18879859 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18879907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19062 + ... + 20027.

It is an arithmetic number, because the mean of its divisors is an integer number (1876320).

Almost surely, 2^18879987 is an apocalyptic number.

18879987 is a deficient number, since it is larger than the sum of its proper divisors (11141133).

18879987 is a wasteful number, since it uses less digits than its factorization.

18879987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39122.

The product of its digits is 2032128, while the sum is 57.

The square root of 18879987 is about 4345.1107005461. The cubic root of 18879987 is about 266.2771481498.

The spelling of 18879987 in words is "eighteen million, eight hundred seventy-nine thousand, nine hundred eighty-seven".