18009779 has 4 divisors (see below), whose sum is σ = 18130800. Its totient is φ = 17888760.

The previous prime is 18009763. The next prime is 18009821. The reversal of 18009779 is 97790081.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 97790081 = 59 ⋅1657459.

It is a cyclic number.

It is not a de Polignac number, because 18009779 - 2⁴ = 18009763 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18009179) 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, 60287 + ... + 60584.

It is an arithmetic number, because the mean of its divisors is an integer number (4532700).

Almost surely, 2^18009779 is an apocalyptic number.

18009779 is a deficient number, since it is larger than the sum of its proper divisors (121021).

18009779 is a wasteful number, since it uses less digits than its factorization.

18009779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 121020.

The product of its (nonzero) digits is 31752, while the sum is 41.

The square root of 18009779 is about 4243.7929968367. The cubic root of 18009779 is about 262.1215905142.

The spelling of 18009779 in words is "eighteen million, nine thousand, seven hundred seventy-nine".