680557 has 4 divisors (see below), whose sum is σ = 685216. Its totient is φ = 675900.

The previous prime is 680539. The next prime is 680567. The reversal of 680557 is 755086.

680557 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, and also an emirpimes, since its reverse is a distinct semiprime: 755086 = 2 ⋅377543.

It is a cyclic number.

It is not a de Polignac number, because 680557 - 2¹⁵ = 647789 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (680507) 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, 2103 + ... + 2404.

It is an arithmetic number, because the mean of its divisors is an integer number (171304).

2⁶⁸⁰⁵⁵⁷ is an apocalyptic number.

It is an amenable number.

680557 is a deficient number, since it is larger than the sum of its proper divisors (4659).

680557 is a wasteful number, since it uses less digits than its factorization.

680557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4658.

The product of its (nonzero) digits is 8400, while the sum is 31.

The square root of 680557 is about 824.9587868494. The cubic root of 680557 is about 87.9605970289.

Subtracting 680557 from its reverse (755086), we obtain a square (74529 = 273²).

The spelling of 680557 in words is "six hundred eighty thousand, five hundred fifty-seven".