686405028666 has 32 divisors (see below), whose sum is σ = 1568951533440. Its totient is φ = 196112503296.

The previous prime is 686405028653. The next prime is 686405028667. The reversal of 686405028666 is 666820504686.

It is not an unprimeable number, because it can be changed into a prime (686405028667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3840850 + ... + 4015586.

It is an arithmetic number, because the mean of its divisors is an integer number (49029735420).

Almost surely, 2^686405028666 is an apocalyptic number.

686405028666 is an abundant number, since it is smaller than the sum of its proper divisors (882546504774).

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

686405028666 is a wasteful number, since it uses less digits than its factorization.

686405028666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 268278.

The product of its (nonzero) digits is 19906560, while the sum is 57.

The spelling of 686405028666 in words is "six hundred eighty-six billion, four hundred five million, twenty-eight thousand, six hundred sixty-six".