1680649 has 8 divisors (see below), whose sum is σ = 1723680. Its totient is φ = 1638336.

The previous prime is 1680647. The next prime is 1680659. The reversal of 1680649 is 9460861.

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 1680649 - 2¹ = 1680647 is a prime.

It is a super-2 number, since 2×1680649² = 5649162122402, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1680643) 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, 12022 + ... + 12160.

It is an arithmetic number, because the mean of its divisors is an integer number (215460).

2^1680649 is an apocalyptic number.

It is an amenable number.

1680649 is a deficient number, since it is larger than the sum of its proper divisors (43031).

1680649 is a wasteful number, since it uses less digits than its factorization.

1680649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 359.

The product of its (nonzero) digits is 10368, while the sum is 34.

The square root of 1680649 is about 1296.3984726927. The cubic root of 1680649 is about 118.8937450422.

The spelling of 1680649 in words is "one million, six hundred eighty thousand, six hundred forty-nine".