1686825 has 90 divisors (see below), whose sum is σ = 3848526. Its totient is φ = 725760.

The previous prime is 1686823. The next prime is 1686827. The reversal of 1686825 is 5286861.

1686825 = 161² + 162² + ... + 209².

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1686823) and next prime (1686827).

It can be written as a sum of positive squares in 3 ways, for example, as 254016 + 1432809 = 504^2 + 1197^2 .

It is not a de Polignac number, because 1686825 - 2¹ = 1686823 is a prime.

Its product of digits (23040) is a multiple of the sum of its prime divisors (32).

1686825 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 1686825.

It is not an unprimeable number, because it can be changed into a prime (1686823) by changing a digit.

It is a polite number, since it can be written in 89 ways as a sum of consecutive naturals, for example, 99217 + ... + 99233.

2^1686825 is an apocalyptic number.

1686825 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1686825 is an abundant number, since it is smaller than the sum of its proper divisors (2161701).

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

1686825 is a wasteful number, since it uses less digits than its factorization.

1686825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53 (or 32 counting only the distinct ones).

The product of its digits is 23040, while the sum is 36.

The square root of 1686825 is about 1298.7782720696. The cubic root of 1686825 is about 119.0392027701.

Adding to 1686825 its sum of digits (36), we get a palindrome (1686861).

The spelling of 1686825 in words is "one million, six hundred eighty-six thousand, eight hundred twenty-five".