657649 has 2 divisors, whose sum is σ = 657650. Its totient is φ = 657648.

The previous prime is 657617. The next prime is 657653. The reversal of 657649 is 946756.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 651249 + 6400 = 807^2 + 80^2 .

It is a cyclic number.

It is not a de Polignac number, because 657649 - 2⁵ = 657617 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (657659) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 328824 + 328825.

It is an arithmetic number, because the mean of its divisors is an integer number (328825).

2⁶⁵⁷⁶⁴⁹ is an apocalyptic number.

It is an amenable number.

657649 is a deficient number, since it is larger than the sum of its proper divisors (1).

657649 is an equidigital number, since it uses as much as digits as its factorization.

657649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 45360, while the sum is 37.

The square root of 657649 is about 810.9556091427. The cubic root of 657649 is about 86.9623741822.

The spelling of 657649 in words is "six hundred fifty-seven thousand, six hundred forty-nine".