686417850 has 72 divisors (see below), whose sum is σ = 1847579292. Its totient is φ = 182707200.

The previous prime is 686417827. The next prime is 686417867. The reversal of 686417850 is 58714686.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 421932681 + 264485169 = 20541^2 + 16263^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 686417796 and 686417805.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 328810 + ... + 330890.

Almost surely, 2^686417850 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 686417850, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (923789646).

686417850 is an abundant number, since it is smaller than the sum of its proper divisors (1161161442).

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

686417850 is a wasteful number, since it uses less digits than its factorization.

686417850 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2832 (or 2824 counting only the distinct ones).

The product of its (nonzero) digits is 322560, while the sum is 45.

The square root of 686417850 is about 26199.5772866663. The cubic root of 686417850 is about 882.1237659320.

The spelling of 686417850 in words is "six hundred eighty-six million, four hundred seventeen thousand, eight hundred fifty".