18601987 has 4 divisors (see below), whose sum is σ = 19055736. Its totient is φ = 18148240.

The previous prime is 18601967. The next prime is 18602027. The reversal of 18601987 is 78910681.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 78910681 = 107 ⋅737483.

It is a de Polignac number, because none of the positive numbers 2^k-18601987 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18601937) 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 3 ways as a sum of consecutive naturals, for example, 226813 + ... + 226894.

It is an arithmetic number, because the mean of its divisors is an integer number (4763934).

Almost surely, 2^18601987 is an apocalyptic number.

18601987 is a deficient number, since it is larger than the sum of its proper divisors (453749).

18601987 is an equidigital number, since it uses as much as digits as its factorization.

18601987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 453748.

The product of its (nonzero) digits is 24192, while the sum is 40.

The square root of 18601987 is about 4313.0020867141. The cubic root of 18601987 is about 264.9637401438.

The spelling of 18601987 in words is "eighteen million, six hundred one thousand, nine hundred eighty-seven".