628666609 has 4 divisors (see below), whose sum is σ = 628775280. Its totient is φ = 628557940.

The previous prime is 628666607. The next prime is 628666627. The reversal of 628666609 is 906666826.

It is a happy number.

628666609 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 628666609 - 2¹ = 628666607 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (628666607) 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, 45139 + ... + 57400.

It is an arithmetic number, because the mean of its divisors is an integer number (157193820).

Almost surely, 2^628666609 is an apocalyptic number.

It is an amenable number.

628666609 is a deficient number, since it is larger than the sum of its proper divisors (108671).

628666609 is a wasteful number, since it uses less digits than its factorization.

628666609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108670.

The product of its (nonzero) digits is 1119744, while the sum is 49.

The square root of 628666609 is about 25073.2249421569. The cubic root of 628666609 is about 856.6566645985.

The spelling of 628666609 in words is "six hundred twenty-eight million, six hundred sixty-six thousand, six hundred nine".