686696693761 has 4 divisors (see below), whose sum is σ = 739519516372. Its totient is φ = 633873871152.

The previous prime is 686696693717. The next prime is 686696693801. The reversal of 686696693761 is 167396696686.

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 184164572736 + 502532121025 = 429144^2 + 708895^2 .

It is a cyclic number.

It is not a de Polignac number, because 686696693761 - 2¹¹ = 686696691713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (686696693461) 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 3 ways as a sum of consecutive naturals, for example, 26411411286 + ... + 26411411311.

It is an arithmetic number, because the mean of its divisors is an integer number (184879879093).

It is a Proth number, since it is equal to 654885 ⋅ 2²⁰ + 1 and 654885 < 2²⁰.

Almost surely, 2^686696693761 is an apocalyptic number.

It is an amenable number.

686696693761 is a deficient number, since it is larger than the sum of its proper divisors (52822822611).

686696693761 is a wasteful number, since it uses less digits than its factorization.

686696693761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52822822610.

The product of its digits is 634894848, while the sum is 73.

The spelling of 686696693761 in words is "six hundred eighty-six billion, six hundred ninety-six million, six hundred ninety-three thousand, seven hundred sixty-one".