18279661 has 4 divisors (see below), whose sum is σ = 18289152. Its totient is φ = 18270172.

The previous prime is 18279643. The next prime is 18279673. The reversal of 18279661 is 16697281.

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 a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 18279661 - 2¹³ = 18271469 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18279061) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 715 + ... + 6088.

It is an arithmetic number, because the mean of its divisors is an integer number (4572288).

Almost surely, 2^18279661 is an apocalyptic number.

It is an amenable number.

18279661 is a deficient number, since it is larger than the sum of its proper divisors (9491).

18279661 is an equidigital number, since it uses as much as digits as its factorization.

18279661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9490.

The product of its digits is 36288, while the sum is 40.

The square root of 18279661 is about 4275.4720207247. The cubic root of 18279661 is about 263.4244280614.

The spelling of 18279661 in words is "eighteen million, two hundred seventy-nine thousand, six hundred sixty-one".