646633 has 4 divisors (see below), whose sum is σ = 696388. Its totient is φ = 596880.

The previous prime is 646631. The next prime is 646637. The reversal of 646633 is 336646.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 336646 = 2 ⋅168323.

It can be written as a sum of positive squares in 2 ways, for example, as 363609 + 283024 = 603^2 + 532^2 .

It is a cyclic number.

It is not a de Polignac number, because 646633 - 2¹ = 646631 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (646631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24858 + ... + 24883.

It is an arithmetic number, because the mean of its divisors is an integer number (174097).

2⁶⁴⁶⁶³³ is an apocalyptic number.

It is an amenable number.

646633 is a deficient number, since it is larger than the sum of its proper divisors (49755).

646633 is a wasteful number, since it uses less digits than its factorization.

646633 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49754.

The product of its digits is 7776, while the sum is 28.

The square root of 646633 is about 804.1349389251. The cubic root of 646633 is about 86.4740809108.

The spelling of 646633 in words is "six hundred forty-six thousand, six hundred thirty-three".