680687257 has 2 divisors, whose sum is σ = 680687258. Its totient is φ = 680687256.

The previous prime is 680687221. The next prime is 680687299. The reversal of 680687257 is 752786086.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 677092441 + 3594816 = 26021^2 + 1896^2 .

It is a cyclic number.

It is not a de Polignac number, because 680687257 - 2⁷ = 680687129 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 680687257.

It is not a weakly prime, because it can be changed into another prime (680637257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340343628 + 340343629.

It is an arithmetic number, because the mean of its divisors is an integer number (340343629).

Almost surely, 2^680687257 is an apocalyptic number.

It is an amenable number.

680687257 is a deficient number, since it is larger than the sum of its proper divisors (1).

680687257 is an equidigital number, since it uses as much as digits as its factorization.

680687257 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1128960, while the sum is 49.

The square root of 680687257 is about 26089.9838443798. The cubic root of 680687257 is about 879.6620848768.

The spelling of 680687257 in words is "six hundred eighty million, six hundred eighty-seven thousand, two hundred fifty-seven".