1680641 has 4 divisors (see below), whose sum is σ = 1704384. Its totient is φ = 1656900.

The previous prime is 1680617. The next prime is 1680643. The reversal of 1680641 is 1460861.

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: 1460861 = 17 ⋅85933.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1680641 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1680641.

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 3 ways as a sum of consecutive naturals, for example, 11765 + ... + 11906.

It is an arithmetic number, because the mean of its divisors is an integer number (426096).

2^1680641 is an apocalyptic number.

It is an amenable number.

1680641 is a deficient number, since it is larger than the sum of its proper divisors (23743).

1680641 is an equidigital number, since it uses as much as digits as its factorization.

1680641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23742.

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 1680641 is about 1296.3953872180. The cubic root of 1680641 is about 118.8935563946.

The spelling of 1680641 in words is "one million, six hundred eighty thousand, six hundred forty-one".