18809569 has 3 divisors (see below), whose sum is σ = 18813907. Its totient is φ = 18805232.

The previous prime is 18809521. The next prime is 18809597. The reversal of 18809569 is 96590881.

The square root of 18809569 is 4337.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 216225 + 18593344 = 465^2 + 4312^2 .

It is not a de Polignac number, because 18809569 - 2⁹ = 18809057 is a prime.

It is a super-2 number, since 2×18809569² = 707599771931522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18809509) 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 2 ways as a sum of consecutive naturals, for example, 2169 + ... + 6505.

Almost surely, 2^18809569 is an apocalyptic number.

18809569 is the 4337-th square number.

18809569 is the 2169-th centered octagonal number.

It is an amenable number.

18809569 is a deficient number, since it is larger than the sum of its proper divisors (4338).

18809569 is an frugal number, since it uses more digits than its factorization.

18809569 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8674 (or 4337 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 46.

The cubic root of 18809569 is about 265.9456849170.

It can be divided in two parts, 1880 and 9569, that added together give a square (11449 = 107²).

The spelling of 18809569 in words is "eighteen million, eight hundred nine thousand, five hundred sixty-nine".