628105809 has 32 divisors (see below), whose sum is σ = 888796800. Its totient is φ = 393935360.

The previous prime is 628105763. The next prime is 628105847. The reversal of 628105809 is 908501826.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-628105809 is a prime.

It is not an unprimeable number, because it can be changed into a prime (628105879) 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 31 ways as a sum of consecutive naturals, for example, 824989 + ... + 825749.

It is an arithmetic number, because the mean of its divisors is an integer number (27774900).

Almost surely, 2^628105809 is an apocalyptic number.

It is an amenable number.

628105809 is a deficient number, since it is larger than the sum of its proper divisors (260690991).

628105809 is a wasteful number, since it uses less digits than its factorization.

628105809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1025.

The product of its (nonzero) digits is 34560, while the sum is 39.

The square root of 628105809 is about 25062.0392027465. The cubic root of 628105809 is about 856.4018628897.

The spelling of 628105809 in words is "six hundred twenty-eight million, one hundred five thousand, eight hundred nine".