18587161 has 4 divisors (see below), whose sum is σ = 18849024. Its totient is φ = 18325300.

The previous prime is 18587159. The next prime is 18587167. The reversal of 18587161 is 16178581.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 16178581 = 293 ⋅55217.

It is a cyclic number.

It is not a de Polignac number, because 18587161 - 2¹ = 18587159 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 18587161.

It is not an unprimeable number, because it can be changed into a prime (18587167) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 130825 + ... + 130966.

It is an arithmetic number, because the mean of its divisors is an integer number (4712256).

Almost surely, 2^18587161 is an apocalyptic number.

It is an amenable number.

18587161 is a deficient number, since it is larger than the sum of its proper divisors (261863).

18587161 is an equidigital number, since it uses as much as digits as its factorization.

18587161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 261862.

The product of its digits is 13440, while the sum is 37.

The square root of 18587161 is about 4311.2829876964. The cubic root of 18587161 is about 264.8933283733.

The spelling of 18587161 in words is "eighteen million, five hundred eighty-seven thousand, one hundred sixty-one".