18720265 has 8 divisors (see below), whose sum is σ = 22987008. Its totient is φ = 14627760.

The previous prime is 18720259. The next prime is 18720337. The reversal of 18720265 is 56202781.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 18720265 - 2³ = 18720257 is a prime.

It is a super-5 number, since 5×18720265⁵ (a number of 38 digits) contains 55555 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 43321 + ... + 43750.

It is an arithmetic number, because the mean of its divisors is an integer number (2873376).

Almost surely, 2^18720265 is an apocalyptic number.

It is an amenable number.

18720265 is a deficient number, since it is larger than the sum of its proper divisors (4266743).

18720265 is an equidigital number, since it uses as much as digits as its factorization.

18720265 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87119.

The product of its (nonzero) digits is 6720, while the sum is 31.

The square root of 18720265 is about 4326.6921545217. The cubic root of 18720265 is about 265.5241317589.

The spelling of 18720265 in words is "eighteen million, seven hundred twenty thousand, two hundred sixty-five".