18920005 has 8 divisors (see below), whose sum is σ = 24450552. Its totient is φ = 13971648.

The previous prime is 18920003. The next prime is 18920047. The reversal of 18920005 is 50002981.

It can be written as a sum of positive squares in 4 ways, for example, as 1887876 + 17032129 = 1374^2 + 4127^2 .

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 18920005 - 2¹ = 18920003 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 (18920003) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 145474 + ... + 145603.

It is an arithmetic number, because the mean of its divisors is an integer number (3056319).

Almost surely, 2^18920005 is an apocalyptic number.

It is an amenable number.

18920005 is a deficient number, since it is larger than the sum of its proper divisors (5530547).

18920005 is a wasteful number, since it uses less digits than its factorization.

18920005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 291095.

The product of its (nonzero) digits is 720, while the sum is 25.

The square root of 18920005 is about 4349.7132089369. The cubic root of 18920005 is about 266.4651489685.

Adding to 18920005 its reverse (50002981), we get a palindrome (68922986).

The spelling of 18920005 in words is "eighteen million, nine hundred twenty thousand, five".