655672009 has 4 divisors (see below), whose sum is σ = 656018820. Its totient is φ = 655325200.

The previous prime is 655672001. The next prime is 655672013. The reversal of 655672009 is 900276556.

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 143328784 + 512343225 = 11972^2 + 22635^2 .

It is a cyclic number.

It is not a de Polignac number, because 655672009 - 2³ = 655672001 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (655672001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 170554 + ... + 174355.

It is an arithmetic number, because the mean of its divisors is an integer number (164004705).

Almost surely, 2^655672009 is an apocalyptic number.

It is an amenable number.

655672009 is a deficient number, since it is larger than the sum of its proper divisors (346811).

655672009 is a wasteful number, since it uses less digits than its factorization.

655672009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 346810.

The product of its (nonzero) digits is 113400, while the sum is 40.

The square root of 655672009 is about 25606.0932006427. The cubic root of 655672009 is about 868.7514609364.

It can be divided in two parts, 65567 and 2009, that added together give a palindrome (67576).

The spelling of 655672009 in words is "six hundred fifty-five million, six hundred seventy-two thousand, nine".