686667663 has 24 divisors (see below), whose sum is σ = 1094193360. Its totient is φ = 411480960.

The previous prime is 686667661. The next prime is 686667671. The reversal of 686667663 is 366766686.

It is a happy number.

It is not a de Polignac number, because 686667663 - 2¹ = 686667661 is a prime.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686667661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 30156 + ... + 47777.

It is an arithmetic number, because the mean of its divisors is an integer number (45591390).

Almost surely, 2^686667663 is an apocalyptic number.

686667663 is a deficient number, since it is larger than the sum of its proper divisors (407525697).

686667663 is a wasteful number, since it uses less digits than its factorization.

686667663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78039 (or 78036 counting only the distinct ones).

The product of its digits is 7838208, while the sum is 54.

The square root of 686667663 is about 26204.3443535609. The cubic root of 686667663 is about 882.2307655079.

It can be divided in two parts, 6866 and 67663, that added together give a square (74529 = 273²).

The spelling of 686667663 in words is "six hundred eighty-six million, six hundred sixty-seven thousand, six hundred sixty-three".