1683649 has 4 divisors (see below), whose sum is σ = 1836720. Its totient is φ = 1530580.

The previous prime is 1683637. The next prime is 1683667. The reversal of 1683649 is 9463861.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 9463861 = 11 ⋅860351.

It is a cyclic number.

It is not a de Polignac number, because 1683649 - 2¹⁵ = 1650881 is a prime.

It is a Duffinian number.

1683649 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1683679) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 76519 + ... + 76540.

It is an arithmetic number, because the mean of its divisors is an integer number (459180).

2^1683649 is an apocalyptic number.

It is an amenable number.

1683649 is a deficient number, since it is larger than the sum of its proper divisors (153071).

1683649 is a wasteful number, since it uses less digits than its factorization.

1683649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 153070.

The product of its digits is 31104, while the sum is 37.

The square root of 1683649 is about 1297.5550084678. Note that the first 3 decimals coincide. The cubic root of 1683649 is about 118.9644457491.

It can be divided in two parts, 1683 and 649, that added together give a palindrome (2332).

The spelling of 1683649 in words is "one million, six hundred eighty-three thousand, six hundred forty-nine".