686464 has 32 divisors (see below), whose sum is σ = 1419840. Its totient is φ = 330240.

The previous prime is 686453. The next prime is 686473. The reversal of 686464 is 464686.

686464 = T₇₂ + T₇₃ + ... + T₁₆₄.

It is a tau number, because it is divible by the number of its divisors (32).

It is a plaindrome in base 9.

It is a congruent number.

It is an unprimeable number.

686464 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3882 + ... + 4054.

It is an arithmetic number, because the mean of its divisors is an integer number (44370).

2⁶⁸⁶⁴⁶⁴ is an apocalyptic number.

686464 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 686464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (709920).

686464 is an abundant number, since it is smaller than the sum of its proper divisors (733376).

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

686464 is a wasteful number, since it uses less digits than its factorization.

686464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218 (or 206 counting only the distinct ones).

The product of its digits is 27648, while the sum is 34.

The square root of 686464 is about 828.5312305520. The cubic root of 686464 is about 88.2143534794.

The spelling of 686464 in words is "six hundred eighty-six thousand, four hundred sixty-four".