686191964923 has 4 divisors (see below), whose sum is σ = 686194444408. Its totient is φ = 686189485440.

The previous prime is 686191964921. The next prime is 686191964981. The reversal of 686191964923 is 329469191686.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 329469191686 = 2 ⋅164734595843.

It is a cyclic number.

It is not a de Polignac number, because 686191964923 - 2¹ = 686191964921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (686191964921) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 763686 + ... + 1398427.

It is an arithmetic number, because the mean of its divisors is an integer number (171548611102).

Almost surely, 2^686191964923 is an apocalyptic number.

686191964923 is a deficient number, since it is larger than the sum of its proper divisors (2479485).

686191964923 is a wasteful number, since it uses less digits than its factorization.

686191964923 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2479484.

The product of its digits is 30233088, while the sum is 64.

The spelling of 686191964923 in words is "six hundred eighty-six billion, one hundred ninety-one million, nine hundred sixty-four thousand, nine hundred twenty-three".