1680399 has 32 divisors (see below), whose sum is σ = 3018240. Its totient is φ = 902016.

The previous prime is 1680377. The next prime is 1680401. The reversal of 1680399 is 9930861.

It is not a de Polignac number, because 1680399 - 2⁷ = 1680271 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1680319) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2952 + ... + 3474.

It is an arithmetic number, because the mean of its divisors is an integer number (94320).

2^1680399 is an apocalyptic number.

1680399 is a deficient number, since it is larger than the sum of its proper divisors (1337841).

1680399 is a wasteful number, since it uses less digits than its factorization.

1680399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 556 (or 550 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 36.

The square root of 1680399 is about 1296.3020481354. The cubic root of 1680399 is about 118.8878495201.

The spelling of 1680399 in words is "one million, six hundred eighty thousand, three hundred ninety-nine".