686661157106 has 4 divisors (see below), whose sum is σ = 1029991735662. Its totient is φ = 343330578552.

The previous prime is 686661157093. The next prime is 686661157121. The reversal of 686661157106 is 601751166686.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 601751166686 = 2 ⋅300875583343.

It can be written as a sum of positive squares in only one way, i.e., 626116125625 + 60545031481 = 791275^2 + 246059^2 .

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 171665289275 + ... + 171665289278.

Almost surely, 2^686661157106 is an apocalyptic number.

686661157106 is a deficient number, since it is larger than the sum of its proper divisors (343330578556).

686661157106 is a wasteful number, since it uses less digits than its factorization.

686661157106 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 343330578555.

The product of its (nonzero) digits is 2177280, while the sum is 53.

The spelling of 686661157106 in words is "six hundred eighty-six billion, six hundred sixty-one million, one hundred fifty-seven thousand, one hundred six".