657043609 has 2 divisors, whose sum is σ = 657043610. Its totient is φ = 657043608.

The previous prime is 657043601. The next prime is 657043613. The reversal of 657043609 is 906340756.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 634032400 + 23011209 = 25180^2 + 4797^2 .

It is a cyclic number.

It is not a de Polignac number, because 657043609 - 2³ = 657043601 is a prime.

It is not a weakly prime, because it can be changed into another prime (657043601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 328521804 + 328521805.

It is an arithmetic number, because the mean of its divisors is an integer number (328521805).

Almost surely, 2^657043609 is an apocalyptic number.

It is an amenable number.

657043609 is a deficient number, since it is larger than the sum of its proper divisors (1).

657043609 is an equidigital number, since it uses as much as digits as its factorization.

657043609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 136080, while the sum is 40.

The square root of 657043609 is about 25632.8618964017. The cubic root of 657043609 is about 869.3568192881.

The spelling of 657043609 in words is "six hundred fifty-seven million, forty-three thousand, six hundred nine".