18864861 has 4 divisors (see below), whose sum is σ = 25153152. Its totient is φ = 12576572.

The previous prime is 18864847. The next prime is 18864871. The reversal of 18864861 is 16846881.

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.

It is a cyclic number.

It is not a de Polignac number, because 18864861 - 2¹¹ = 18862813 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18864841) 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 3 ways as a sum of consecutive naturals, for example, 3144141 + ... + 3144146.

It is an arithmetic number, because the mean of its divisors is an integer number (6288288).

Almost surely, 2^18864861 is an apocalyptic number.

It is an amenable number.

18864861 is a deficient number, since it is larger than the sum of its proper divisors (6288291).

18864861 is an equidigital number, since it uses as much as digits as its factorization.

18864861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6288290.

The product of its digits is 73728, while the sum is 42.

The square root of 18864861 is about 4343.3697747256. The cubic root of 18864861 is about 266.2060184355.

The spelling of 18864861 in words is "eighteen million, eight hundred sixty-four thousand, eight hundred sixty-one".