1689680 has 20 divisors (see below), whose sum is σ = 3928692. Its totient is φ = 675840.

The previous prime is 1689661. The next prime is 1689703. The reversal of 1689680 is 869861.

It can be written as a sum of positive squares in 2 ways, for example, as 929296 + 760384 = 964^2 + 872^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10481 + ... + 10640.

2^1689680 is an apocalyptic number.

1689680 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1689680 is an abundant number, since it is smaller than the sum of its proper divisors (2239012).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1689680 is a wasteful number, since it uses less digits than its factorization.

1689680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21134 (or 21128 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 38.

The square root of 1689680 is about 1299.8769172502. The cubic root of 1689680 is about 119.1063240116.

The spelling of 1689680 in words is "one million, six hundred eighty-nine thousand, six hundred eighty".