18409445 has 4 divisors (see below), whose sum is σ = 22091340. Its totient is φ = 14727552.

The previous prime is 18409439. The next prime is 18409459. The reversal of 18409445 is 54490481.

It is a happy number.

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 6145441 + 12264004 = 2479^2 + 3502^2 .

It is a cyclic number.

It is not a de Polignac number, because 18409445 - 2¹⁰ = 18408421 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1840940 + ... + 1840949.

It is an arithmetic number, because the mean of its divisors is an integer number (5522835).

Almost surely, 2^18409445 is an apocalyptic number.

It is an amenable number.

18409445 is a deficient number, since it is larger than the sum of its proper divisors (3681895).

18409445 is an equidigital number, since it uses as much as digits as its factorization.

18409445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3681894.

The product of its (nonzero) digits is 23040, while the sum is 35.

The square root of 18409445 is about 4290.6229151488. The cubic root of 18409445 is about 264.0463885809.

The spelling of 18409445 in words is "eighteen million, four hundred nine thousand, four hundred forty-five".