646249 has 4 divisors (see below), whose sum is σ = 648064. Its totient is φ = 644436.

The previous prime is 646237. The next prime is 646253. The reversal of 646249 is 942646.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 646249 - 2⁹ = 645737 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 646249.

It is not an unprimeable number, because it can be changed into a prime (646259) by changing a digit.

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 in 3 ways as a sum of consecutive naturals, for example, 177 + ... + 1150.

It is an arithmetic number, because the mean of its divisors is an integer number (162016).

2⁶⁴⁶²⁴⁹ is an apocalyptic number.

It is an amenable number.

646249 is a deficient number, since it is larger than the sum of its proper divisors (1815).

646249 is a wasteful number, since it uses less digits than its factorization.

646249 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1814.

The product of its digits is 10368, while the sum is 31.

The square root of 646249 is about 803.8961375700. The cubic root of 646249 is about 86.4569601111.

The spelling of 646249 in words is "six hundred forty-six thousand, two hundred forty-nine".