686478773 has 4 divisors (see below), whose sum is σ = 688516140. Its totient is φ = 684441408.

The previous prime is 686478761. The next prime is 686478781. The reversal of 686478773 is 377874686.

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 474281284 + 212197489 = 21778^2 + 14567^2 .

It is a cyclic number.

It is not a de Polignac number, because 686478773 - 2¹⁴ = 686462389 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686478713) 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, 1018178 + ... + 1018851.

It is an arithmetic number, because the mean of its divisors is an integer number (172129035).

Almost surely, 2^686478773 is an apocalyptic number.

It is an amenable number.

686478773 is a deficient number, since it is larger than the sum of its proper divisors (2037367).

686478773 is a wasteful number, since it uses less digits than its factorization.

686478773 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2037366.

The product of its digits is 9483264, while the sum is 56.

The square root of 686478773 is about 26200.7399322996. The cubic root of 686478773 is about 882.1498627846.

The spelling of 686478773 in words is "six hundred eighty-six million, four hundred seventy-eight thousand, seven hundred seventy-three".