687856277 has 2 divisors, whose sum is σ = 687856278. Its totient is φ = 687856276.

The previous prime is 687856243. The next prime is 687856319. The reversal of 687856277 is 772658786.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 568631716 + 119224561 = 23846^2 + 10919^2 .

It is a cyclic number.

It is not a de Polignac number, because 687856277 - 2²⁴ = 671079061 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (687856777) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343928138 + 343928139.

It is an arithmetic number, because the mean of its divisors is an integer number (343928139).

Almost surely, 2^687856277 is an apocalyptic number.

It is an amenable number.

687856277 is a deficient number, since it is larger than the sum of its proper divisors (1).

687856277 is an equidigital number, since it uses as much as digits as its factorization.

687856277 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7902720, while the sum is 56.

The square root of 687856277 is about 26227.0142601097. The cubic root of 687856277 is about 882.7395159172.

The spelling of 687856277 in words is "six hundred eighty-seven million, eight hundred fifty-six thousand, two hundred seventy-seven".