1643606 has 4 divisors (see below), whose sum is σ = 2465412. Its totient is φ = 821802.

The previous prime is 1643599. The next prime is 1643617. The reversal of 1643606 is 6063461.

1643606 is nontrivially palindromic in base 8.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 6063461 = 61 ⋅99401.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410900 + ... + 410903.

It is an arithmetic number, because the mean of its divisors is an integer number (616353).

2^1643606 is an apocalyptic number.

1643606 is a deficient number, since it is larger than the sum of its proper divisors (821806).

1643606 is an equidigital number, since it uses as much as digits as its factorization.

1643606 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 821805.

The product of its (nonzero) digits is 2592, while the sum is 26.

The square root of 1643606 is about 1282.0319808804. The cubic root of 1643606 is about 118.0137396622.

The spelling of 1643606 in words is "one million, six hundred forty-three thousand, six hundred six".