1643960 has 32 divisors (see below), whose sum is σ = 3756240. Its totient is φ = 647424.

The previous prime is 1643959. The next prime is 1643963. The reversal of 1643960 is 693461.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1643963) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2639 + ... + 3201.

2^1643960 is an apocalyptic number.

1643960 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 1643960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1878120).

1643960 is an abundant number, since it is smaller than the sum of its proper divisors (2112280).

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

1643960 is a wasteful number, since it uses less digits than its factorization.

1643960 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 647 (or 643 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 29.

The square root of 1643960 is about 1282.1700355257. The cubic root of 1643960 is about 118.0222116571.

The spelling of 1643960 in words is "one million, six hundred forty-three thousand, nine hundred sixty".