1644646 has 4 divisors (see below), whose sum is σ = 2466972. Its totient is φ = 822322.

The previous prime is 1644641. The next prime is 1644653. The reversal of 1644646 is 6464461.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1644641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 411160 + ... + 411163.

It is an arithmetic number, because the mean of its divisors is an integer number (616743).

2^1644646 is an apocalyptic number.

1644646 is a deficient number, since it is larger than the sum of its proper divisors (822326).

1644646 is an equidigital number, since it uses as much as digits as its factorization.

1644646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 822325.

The product of its digits is 13824, while the sum is 31.

The square root of 1644646 is about 1282.4375228447. The cubic root of 1644646 is about 118.0386256774.

The spelling of 1644646 in words is "one million, six hundred forty-four thousand, six hundred forty-six".