18678561 has 16 divisors (see below), whose sum is σ = 27414720. Its totient is φ = 11217920.

The previous prime is 18678559. The next prime is 18678587. The reversal of 18678561 is 16587681.

It is a cyclic number.

It is not a de Polignac number, because 18678561 - 2¹ = 18678559 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18678511) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1225 + ... + 6233.

It is an arithmetic number, because the mean of its divisors is an integer number (1713420).

Almost surely, 2^18678561 is an apocalyptic number.

18678561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18678561 is a deficient number, since it is larger than the sum of its proper divisors (8736159).

18678561 is a wasteful number, since it uses less digits than its factorization.

18678561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5136.

The product of its digits is 80640, while the sum is 42.

The square root of 18678561 is about 4321.8700813421. The cubic root of 18678561 is about 265.3268116977.

The spelling of 18678561 in words is "eighteen million, six hundred seventy-eight thousand, five hundred sixty-one".