686674777 has 4 divisors (see below), whose sum is σ = 687364516. Its totient is φ = 685985040.

The previous prime is 686674771. The next prime is 686674787. The reversal of 686674777 is 777476686.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 259177801 + 427496976 = 16099^2 + 20676^2 .

It is a cyclic number.

It is not a de Polignac number, because 686674777 - 2¹¹ = 686672729 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (686674771) 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 in 3 ways as a sum of consecutive naturals, for example, 343374 + ... + 345367.

It is an arithmetic number, because the mean of its divisors is an integer number (171841129).

Almost surely, 2^686674777 is an apocalyptic number.

It is an amenable number.

686674777 is a deficient number, since it is larger than the sum of its proper divisors (689739).

686674777 is an equidigital number, since it uses as much as digits as its factorization.

686674777 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 689738.

The product of its digits is 16595712, while the sum is 58.

The square root of 686674777 is about 26204.4800940603. The cubic root of 686674777 is about 882.2338121870.

The spelling of 686674777 in words is "six hundred eighty-six million, six hundred seventy-four thousand, seven hundred seventy-seven".