1643996 has 6 divisors (see below), whose sum is σ = 2877000. Its totient is φ = 821996.

The previous prime is 1643989. The next prime is 1644001. The reversal of 1643996 is 6993461.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 205496 + ... + 205503.

It is an arithmetic number, because the mean of its divisors is an integer number (479500).

2^1643996 is an apocalyptic number.

It is an amenable number.

1643996 is a deficient number, since it is larger than the sum of its proper divisors (1233004).

1643996 is a wasteful number, since it uses less digits than its factorization.

1643996 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 411003 (or 411001 counting only the distinct ones).

The product of its digits is 34992, while the sum is 38.

The square root of 1643996 is about 1282.1840741485. The cubic root of 1643996 is about 118.0230731478.

The spelling of 1643996 in words is "one million, six hundred forty-three thousand, nine hundred ninety-six".