686218071 has 32 divisors (see below), whose sum is σ = 1151428608. Its totient is φ = 353132640.

The previous prime is 686218019. The next prime is 686218103. The reversal of 686218071 is 170812686.

It is not a de Polignac number, because 686218071 - 2¹⁴ = 686201687 is a prime.

It is a super-2 number, since 2×686218071² = 941790481933922082, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686213071) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10836 + ... + 38598.

It is an arithmetic number, because the mean of its divisors is an integer number (35982144).

Almost surely, 2^686218071 is an apocalyptic number.

686218071 is a deficient number, since it is larger than the sum of its proper divisors (465210537).

686218071 is a wasteful number, since it uses less digits than its factorization.

686218071 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27891.

The product of its (nonzero) digits is 32256, while the sum is 39.

The square root of 686218071 is about 26195.7643713636. The cubic root of 686218071 is about 882.0381781696.

The spelling of 686218071 in words is "six hundred eighty-six million, two hundred eighteen thousand, seventy-one".