687655373 has 2 divisors, whose sum is σ = 687655374. Its totient is φ = 687655372.

The previous prime is 687655247. The next prime is 687655393. The reversal of 687655373 is 373556786.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 484792324 + 202863049 = 22018^2 + 14243^2 .

It is a cyclic number.

It is not a de Polignac number, because 687655373 - 2²⁰ = 686606797 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (687655393) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343827686 + 343827687.

It is an arithmetic number, because the mean of its divisors is an integer number (343827687).

Almost surely, 2^687655373 is an apocalyptic number.

It is an amenable number.

687655373 is a deficient number, since it is larger than the sum of its proper divisors (1).

687655373 is an equidigital number, since it uses as much as digits as its factorization.

687655373 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3175200, while the sum is 50.

The square root of 687655373 is about 26223.1838837316. The cubic root of 687655373 is about 882.6535661946.

The spelling of 687655373 in words is "six hundred eighty-seven million, six hundred fifty-five thousand, three hundred seventy-three".