18745987 has 6 divisors (see below), whose sum is σ = 20299092. Its totient is φ = 17303832.

The previous prime is 18745967. The next prime is 18746003. The reversal of 18745987 is 78954781.

It is not a de Polignac number, because 18745987 - 2¹⁹ = 18221699 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18745987.

It is not an unprimeable number, because it can be changed into a prime (18745967) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 55293 + ... + 55630.

It is an arithmetic number, because the mean of its divisors is an integer number (3383182).

Almost surely, 2^18745987 is an apocalyptic number.

18745987 is a deficient number, since it is larger than the sum of its proper divisors (1553105).

18745987 is a wasteful number, since it uses less digits than its factorization.

18745987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110949 (or 110936 counting only the distinct ones).

The product of its digits is 564480, while the sum is 49.

The square root of 18745987 is about 4329.6636127995. The cubic root of 18745987 is about 265.6456878374.

The spelling of 18745987 in words is "eighteen million, seven hundred forty-five thousand, nine hundred eighty-seven".