1643959 has 2 divisors, whose sum is σ = 1643960. Its totient is φ = 1643958.

The previous prime is 1643893. The next prime is 1643963. The reversal of 1643959 is 9593461.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1643959 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1643969) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 821979 + 821980.

It is an arithmetic number, because the mean of its divisors is an integer number (821980).

2^1643959 is an apocalyptic number.

1643959 is a deficient number, since it is larger than the sum of its proper divisors (1).

1643959 is an equidigital number, since it uses as much as digits as its factorization.

1643959 is an evil number, because the sum of its binary digits is even.

The product of its digits is 29160, while the sum is 37.

The square root of 1643959 is about 1282.1696455618. The cubic root of 1643959 is about 118.0221877266.

The spelling of 1643959 in words is "one million, six hundred forty-three thousand, nine hundred fifty-nine".