686408719 has 4 divisors (see below), whose sum is σ = 704960344. Its totient is φ = 667857096.

The previous prime is 686408651. The next prime is 686408747. The reversal of 686408719 is 917804686.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 917804686 = 2 ⋅458902343.

It is a cyclic number.

It is not a de Polignac number, because 686408719 - 2¹³ = 686400527 is a prime.

It is a super-2 number, since 2×686408719² = 942313859038441922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686408519) 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, 9275757 + ... + 9275830.

It is an arithmetic number, because the mean of its divisors is an integer number (176240086).

Almost surely, 2^686408719 is an apocalyptic number.

686408719 is a deficient number, since it is larger than the sum of its proper divisors (18551625).

686408719 is a wasteful number, since it uses less digits than its factorization.

686408719 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18551624.

The product of its (nonzero) digits is 580608, while the sum is 49.

The square root of 686408719 is about 26199.4030275501. The cubic root of 686408719 is about 882.1198544623.

The spelling of 686408719 in words is "six hundred eighty-six million, four hundred eight thousand, seven hundred nineteen".