1643040 has 144 divisors (see below), whose sum is σ = 6447168. Its totient is φ = 373248.

The previous prime is 1643039. The next prime is 1643069. The reversal of 1643040 is 403461.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a zygodrome in base 6.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9999 + ... + 10161.

It is an arithmetic number, because the mean of its divisors is an integer number (44772).

2^1643040 is an apocalyptic number.

1643040 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 1643040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3223584).

1643040 is an abundant number, since it is smaller than the sum of its proper divisors (4804128).

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

1643040 is a wasteful number, since it uses less digits than its factorization.

1643040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 191 (or 180 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 1643040 is about 1281.8112185498. The cubic root of 1643040 is about 118.0001915155. Note that the first 3 decimals are identical.

The spelling of 1643040 in words is "one million, six hundred forty-three thousand, forty".