686745 has 16 divisors (see below), whose sum is σ = 1221120. Its totient is φ = 366192.

The previous prime is 686737. The next prime is 686761. The reversal of 686745 is 547686.

It is a happy number.

It is not a de Polignac number, because 686745 - 2³ = 686737 is a prime.

It is a nialpdrome in base 15.

It is an unprimeable 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, 2409 + ... + 2678.

It is an arithmetic number, because the mean of its divisors is an integer number (76320).

2⁶⁸⁶⁷⁴⁵ is an apocalyptic number.

It is an amenable number.

686745 is a deficient number, since it is larger than the sum of its proper divisors (534375).

686745 is a wasteful number, since it uses less digits than its factorization.

686745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5101 (or 5095 counting only the distinct ones).

The product of its digits is 40320, while the sum is 36.

The square root of 686745 is about 828.7007903942. The cubic root of 686745 is about 88.2263885130.

It can be divided in two parts, 686 and 745, that added together give a triangular number (1431 = T₅₃).

The spelling of 686745 in words is "six hundred eighty-six thousand, seven hundred forty-five".