1681749 has 16 divisors (see below), whose sum is σ = 2512000. Its totient is φ = 1111968.

The previous prime is 1681723. The next prime is 1681787. The reversal of 1681749 is 9471861.

It is not a de Polignac number, because 1681749 - 2⁵ = 1681717 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a plaindrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1681349) by changing a digit.

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, 5217 + ... + 5529.

It is an arithmetic number, because the mean of its divisors is an integer number (157000).

2^1681749 is an apocalyptic number.

It is an amenable number.

1681749 is a deficient number, since it is larger than the sum of its proper divisors (830251).

1681749 is a wasteful number, since it uses less digits than its factorization.

1681749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 521 (or 515 counting only the distinct ones).

The product of its digits is 12096, while the sum is 36.

The square root of 1681749 is about 1296.8226555701. The cubic root of 1681749 is about 118.9196783963.

The spelling of 1681749 in words is "one million, six hundred eighty-one thousand, seven hundred forty-nine".