1723681 has 8 divisors (see below), whose sum is σ = 1870344. Its totient is φ = 1582080.

The previous prime is 1723669. The next prime is 1723721. The reversal of 1723681 is 1863271.

It can be written as a sum of positive squares in 4 ways, for example, as 245025 + 1478656 = 495^2 + 1216^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1723681 - 2¹¹ = 1721633 is a prime.

It is a super-2 number, since 2×1723681² = 5942152379522, which contains 22 as substring.

It is a Duffinian number.

1723681 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1723621) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 540 + ... + 1933.

It is an arithmetic number, because the mean of its divisors is an integer number (233793).

2^1723681 is an apocalyptic number.

It is an amenable number.

1723681 is a deficient number, since it is larger than the sum of its proper divisors (146663).

1723681 is a wasteful number, since it uses less digits than its factorization.

1723681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2531.

The product of its digits is 2016, while the sum is 28.

The square root of 1723681 is about 1312.8903229135. The cubic root of 1723681 is about 119.8999397375.

The spelling of 1723681 in words is "one million, seven hundred twenty-three thousand, six hundred eighty-one".