1605840 has 40 divisors (see below), whose sum is σ = 4978848. Its totient is φ = 428160.

The previous prime is 1605839. The next prime is 1605853. The reversal of 1605840 is 485061.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 1605840.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3106 + ... + 3585.

2^1605840 is an apocalyptic number.

1605840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1605840 is an abundant number, since it is smaller than the sum of its proper divisors (3373008).

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

1605840 is a wasteful number, since it uses less digits than its factorization.

1605840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6707 (or 6701 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 24.

The square root of 1605840 is about 1267.2174241226. The cubic root of 1605840 is about 117.1028389410.

The spelling of 1605840 in words is "one million, six hundred five thousand, eight hundred forty".