686665122 has 128 divisors (see below), whose sum is σ = 1724405760. Its totient is φ = 179082240.

The previous prime is 686665121. The next prime is 686665123. The reversal of 686665122 is 221566686.

It is an interprime number because it is at equal distance from previous prime (686665121) and next prime (686665123).

It is a super-3 number, since 3×686665122³ (a number of 27 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (686665121) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2610763 + ... + 2611025.

It is an arithmetic number, because the mean of its divisors is an integer number (13471920).

Almost surely, 2^686665122 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 686665122, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (862202880).

686665122 is an abundant number, since it is smaller than the sum of its proper divisors (1037740638).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

686665122 is a wasteful number, since it uses less digits than its factorization.

686665122 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 488.

The product of its digits is 207360, while the sum is 42.

The square root of 686665122 is about 26204.2958691891. The cubic root of 686665122 is about 882.2296772808.

The spelling of 686665122 in words is "six hundred eighty-six million, six hundred sixty-five thousand, one hundred twenty-two".