1643560 has 32 divisors (see below), whose sum is σ = 3917160. Its totient is φ = 618496.

The previous prime is 1643539. The next prime is 1643581. The reversal of 1643560 is 653461.

It is an interprime number because it is at equal distance from previous prime (1643539) and next prime (1643581).

It can be written as a sum of positive squares in 4 ways, for example, as 1643524 + 36 = 1282^2 + 6^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 529 + ... + 1888.

2^1643560 is an apocalyptic number.

1643560 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1643560 is an abundant number, since it is smaller than the sum of its proper divisors (2273600).

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

1643560 is a wasteful number, since it uses less digits than its factorization.

1643560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2445 (or 2441 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 25.

The square root of 1643560 is about 1282.0140404847. The cubic root of 1643560 is about 118.0126386922.

Subtracting from 1643560 its reverse (653461), we obtain a palindrome (990099).

The spelling of 1643560 in words is "one million, six hundred forty-three thousand, five hundred sixty".