18728005 has 8 divisors (see below), whose sum is σ = 22996512. Its totient is φ = 14633808.

The previous prime is 18727991. The next prime is 18728009. The reversal of 18728005 is 50082781.

18728005 = 1364² + 1365² + ... + 1373².

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

It is a cyclic number.

It is not a de Polignac number, because 18728005 - 2¹¹ = 18725957 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18728009) by changing a digit.

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, 43339 + ... + 43768.

It is an arithmetic number, because the mean of its divisors is an integer number (2874564).

Almost surely, 2^18728005 is an apocalyptic number.

It is an amenable number.

18728005 is a deficient number, since it is larger than the sum of its proper divisors (4268507).

18728005 is an equidigital number, since it uses as much as digits as its factorization.

18728005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87155.

The product of its (nonzero) digits is 4480, while the sum is 31.

The square root of 18728005 is about 4327.5865098228. The cubic root of 18728005 is about 265.5607208707.

The spelling of 18728005 in words is "eighteen million, seven hundred twenty-eight thousand, five".