686742 has 32 divisors (see below), whose sum is σ = 1596672. Its totient is φ = 192864.

The previous prime is 686737. The next prime is 686761. The reversal of 686742 is 247686.

It is a super-2 number, since 2×686742² = 943229149128, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

686742 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3388 + ... + 3584.

It is an arithmetic number, because the mean of its divisors is an integer number (49896).

2⁶⁸⁶⁷⁴² is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 686742, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (798336).

686742 is an abundant number, since it is smaller than the sum of its proper divisors (909930).

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

686742 is a wasteful number, since it uses less digits than its factorization.

686742 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 292.

The product of its digits is 16128, while the sum is 33.

The square root of 686742 is about 828.6989803300. The cubic root of 686742 is about 88.2262600424.

The spelling of 686742 in words is "six hundred eighty-six thousand, seven hundred forty-two".