687506257 has 2 divisors, whose sum is σ = 687506258. Its totient is φ = 687506256.

The previous prime is 687506233. The next prime is 687506263. The reversal of 687506257 is 752605786.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 599221441 + 88284816 = 24479^2 + 9396^2 .

It is a cyclic number.

It is not a de Polignac number, because 687506257 - 2¹⁹ = 686981969 is a prime.

It is not a weakly prime, because it can be changed into another prime (687506207) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343753128 + 343753129.

It is an arithmetic number, because the mean of its divisors is an integer number (343753129).

Almost surely, 2^687506257 is an apocalyptic number.

It is an amenable number.

687506257 is a deficient number, since it is larger than the sum of its proper divisors (1).

687506257 is an equidigital number, since it uses as much as digits as its factorization.

687506257 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 705600, while the sum is 46.

The square root of 687506257 is about 26220.3405202907. The cubic root of 687506257 is about 882.5897613252.

It can be divided in two parts, 687 and 506257, that added together give a square (506944 = 712²).

The spelling of 687506257 in words is "six hundred eighty-seven million, five hundred six thousand, two hundred fifty-seven".