18618861 has 4 divisors (see below), whose sum is σ = 24825152. Its totient is φ = 12412572.

The previous prime is 18618857. The next prime is 18618863. The reversal of 18618861 is 16881681.

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 not a de Polignac number, because 18618861 - 2² = 18618857 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18618863) 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, 3103141 + ... + 3103146.

It is an arithmetic number, because the mean of its divisors is an integer number (6206288).

Almost surely, 2^18618861 is an apocalyptic number.

It is an amenable number.

18618861 is a deficient number, since it is larger than the sum of its proper divisors (6206291).

18618861 is an equidigital number, since it uses as much as digits as its factorization.

18618861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6206290.

The product of its digits is 18432, while the sum is 39.

The square root of 18618861 is about 4314.9578213466. The cubic root of 18618861 is about 265.0438327873.

The spelling of 18618861 in words is "eighteen million, six hundred eighteen thousand, eight hundred sixty-one".