687839617 has 2 divisors, whose sum is σ = 687839618. Its totient is φ = 687839616.

The previous prime is 687839611. The next prime is 687839627. The reversal of 687839617 is 716938786.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 442008576 + 245831041 = 21024^2 + 15679^2 .

It is a cyclic number.

It is not a de Polignac number, because 687839617 - 2⁷ = 687839489 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (687839611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343919808 + 343919809.

It is an arithmetic number, because the mean of its divisors is an integer number (343919809).

Almost surely, 2^687839617 is an apocalyptic number.

It is an amenable number.

687839617 is a deficient number, since it is larger than the sum of its proper divisors (1).

687839617 is an equidigital number, since it uses as much as digits as its factorization.

687839617 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3048192, while the sum is 55.

The square root of 687839617 is about 26226.6966467377. The cubic root of 687839617 is about 882.7323891575.

It can be divided in two parts, 68783 and 9617, that added together give a square (78400 = 280²).

The spelling of 687839617 in words is "six hundred eighty-seven million, eight hundred thirty-nine thousand, six hundred seventeen".