1678725 has 30 divisors (see below), whose sum is σ = 3113330. Its totient is φ = 894240.

The previous prime is 1678717. The next prime is 1678739. The reversal of 1678725 is 5278761.

It can be written as a sum of positive squares in 3 ways, for example, as 136161 + 1542564 = 369^2 + 1242^2 .

It is not a de Polignac number, because 1678725 - 2³ = 1678717 is a prime.

It is an Ulam number.

It is an alternating number because its digits alternate between odd and even.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1678725.

It is a congruent number.

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 29 ways as a sum of consecutive naturals, for example, 1611 + ... + 2439.

2^1678725 is an apocalyptic number.

1678725 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1678725 is a deficient number, since it is larger than the sum of its proper divisors (1434605).

1678725 is an equidigital number, since it uses as much as digits as its factorization.

1678725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 851 (or 837 counting only the distinct ones).

The product of its digits is 23520, while the sum is 36.

The square root of 1678725 is about 1295.6562043999. The cubic root of 1678725 is about 118.8483580296.

Adding to 1678725 its sum of digits (36), we get a palindrome (1678761).

The spelling of 1678725 in words is "one million, six hundred seventy-eight thousand, seven hundred twenty-five".