657616409 has 2 divisors, whose sum is σ = 657616410. Its totient is φ = 657616408.

The previous prime is 657616403. The next prime is 657616469. The reversal of 657616409 is 904616756.

It is a happy number.

657616409 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 618616384 + 39000025 = 24872^2 + 6245^2 .

It is a cyclic number.

It is not a de Polignac number, because 657616409 - 2⁸ = 657616153 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 657616409.

It is not a weakly prime, because it can be changed into another prime (657616403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 328808204 + 328808205.

It is an arithmetic number, because the mean of its divisors is an integer number (328808205).

Almost surely, 2^657616409 is an apocalyptic number.

It is an amenable number.

657616409 is a deficient number, since it is larger than the sum of its proper divisors (1).

657616409 is an equidigital number, since it uses as much as digits as its factorization.

657616409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 272160, while the sum is 44.

The square root of 657616409 is about 25644.0326196954. The cubic root of 657616409 is about 869.6093763192.

The spelling of 657616409 in words is "six hundred fifty-seven million, six hundred sixteen thousand, four hundred nine".