18867609 has 6 divisors (see below), whose sum is σ = 27253226. Its totient is φ = 12578400.

The previous prime is 18867599. The next prime is 18867617. The reversal of 18867609 is 90676881.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 18662400 + 205209 = 4320^2 + 453^2 .

It is not a de Polignac number, because 18867609 - 2⁴ = 18867593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18867679) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1048192 + ... + 1048209.

Almost surely, 2^18867609 is an apocalyptic number.

It is an amenable number.

18867609 is a deficient number, since it is larger than the sum of its proper divisors (8385617).

18867609 is a wasteful number, since it uses less digits than its factorization.

18867609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2096407 (or 2096404 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 45.

The square root of 18867609 is about 4343.6861074438. The cubic root of 18867609 is about 266.2189436764.

The spelling of 18867609 in words is "eighteen million, eight hundred sixty-seven thousand, six hundred nine".