686666000 has 40 divisors (see below), whose sum is σ = 1660363224. Its totient is φ = 274665600.

The previous prime is 686665981. The next prime is 686666009. The reversal of 686666000 is 666686.

It can be written as a sum of positive squares in 4 ways, for example, as 16384 + 686649616 = 128^2 + 26204^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (686666009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 169667 + ... + 173666.

Almost surely, 2^686666000 is an apocalyptic number.

It is an amenable number.

686666000 is an abundant number, since it is smaller than the sum of its proper divisors (973697224).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

686666000 is a wasteful number, since it uses less digits than its factorization.

686666000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 343356 (or 343340 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 38.

The square root of 686666000 is about 26204.3126221620. The cubic root of 686666000 is about 882.2300532998.

The spelling of 686666000 in words is "six hundred eighty-six million, six hundred sixty-six thousand".