1681520 has 20 divisors (see below), whose sum is σ = 3909720. Its totient is φ = 672576.

The previous prime is 1681517. The next prime is 1681541. The reversal of 1681520 is 251861.

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, 10430 + ... + 10589.

It is an arithmetic number, because the mean of its divisors is an integer number (195486).

2^1681520 is an apocalyptic number.

1681520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1681520 is an abundant number, since it is smaller than the sum of its proper divisors (2228200).

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

1681520 is a wasteful number, since it uses less digits than its factorization.

1681520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21032 (or 21026 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 23.

The square root of 1681520 is about 1296.7343598440. The cubic root of 1681520 is about 118.9142804758.

The spelling of 1681520 in words is "one million, six hundred eighty-one thousand, five hundred twenty".