1681680 has 240 divisors, whose sum is σ = 7124544. Its totient is φ = 322560.

The previous prime is 1681679. The next prime is 1681703. The reversal of 1681680 is 861861.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 129354 + ... + 129366.

2^1681680 is an apocalyptic number.

1681680 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1681680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3562272).

1681680 is an abundant number, since it is smaller than the sum of its proper divisors (5442864).

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

1681680 is a wasteful number, since it uses less digits than its factorization.

1681680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54 (or 41 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 30.

The square root of 1681680 is about 1296.7960518139. The cubic root of 1681680 is about 118.9180520002.

The spelling of 1681680 in words is "one million, six hundred eighty-one thousand, six hundred eighty".