18920609 has 4 divisors (see below), whose sum is σ = 20033604. Its totient is φ = 17807616.

The previous prime is 18920569. The next prime is 18920621. The reversal of 18920609 is 90602981.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 10923025 + 7997584 = 3305^2 + 2828^2 .

It is a cyclic number.

It is not a de Polignac number, because 18920609 - 2⁸ = 18920353 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18920809) 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, 556472 + ... + 556505.

It is an arithmetic number, because the mean of its divisors is an integer number (5008401).

Almost surely, 2^18920609 is an apocalyptic number.

It is an amenable number.

18920609 is a deficient number, since it is larger than the sum of its proper divisors (1112995).

18920609 is a wasteful number, since it uses less digits than its factorization.

18920609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1112994.

The product of its (nonzero) digits is 7776, while the sum is 35.

The square root of 18920609 is about 4349.7826382476. The cubic root of 18920609 is about 266.4679844722.

The spelling of 18920609 in words is "eighteen million, nine hundred twenty thousand, six hundred nine".