686017440 has 72 divisors (see below), whose sum is σ = 2341039428. Its totient is φ = 182937600.

The previous prime is 686017433. The next prime is 686017441. The reversal of 686017440 is 44710686.

686017440 is a `hidden beast` number, since 6 + 8 + 601 + 7 + 4 + 40 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 676208016 + 9809424 = 26004^2 + 3132^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 686017395 and 686017404.

It is not an unprimeable number, because it can be changed into a prime (686017441) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 236761 + ... + 239640.

Almost surely, 2^686017440 is an apocalyptic number.

686017440 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

686017440 is an abundant number, since it is smaller than the sum of its proper divisors (1655021988).

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

686017440 is a wasteful number, since it uses less digits than its factorization.

686017440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 476422 (or 476411 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 36.

The square root of 686017440 is about 26191.9346364487. The cubic root of 686017440 is about 881.9522086805.

The spelling of 686017440 in words is "six hundred eighty-six million, seventeen thousand, four hundred forty".