1649663 has 4 divisors (see below), whose sum is σ = 1746720. Its totient is φ = 1552608.

The previous prime is 1649657. The next prime is 1649671. The reversal of 1649663 is 3669461.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3669461 = 139 ⋅26399.

It is a cyclic number.

It is not a de Polignac number, because 1649663 - 2⁴ = 1649647 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1649693) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 48503 + ... + 48536.

It is an arithmetic number, because the mean of its divisors is an integer number (436680).

2^1649663 is an apocalyptic number.

1649663 is a deficient number, since it is larger than the sum of its proper divisors (97057).

1649663 is an equidigital number, since it uses as much as digits as its factorization.

1649663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97056.

The product of its digits is 23328, while the sum is 35.

The square root of 1649663 is about 1284.3920740958. The cubic root of 1649663 is about 118.1585296231.

The spelling of 1649663 in words is "one million, six hundred forty-nine thousand, six hundred sixty-three".