646826 has 4 divisors (see below), whose sum is σ = 970242. Its totient is φ = 323412.

The previous prime is 646823. The next prime is 646831. The reversal of 646826 is 628646.

It is a happy number.

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

It can be written as a sum of positive squares in only one way, i.e., 421201 + 225625 = 649^2 + 475^2 .

It is a junction number, because it is equal to n+sod(n) for n = 646792 and 646801.

It is not an unprimeable number, because it can be changed into a prime (646823) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 161705 + ... + 161708.

2⁶⁴⁶⁸²⁶ is an apocalyptic number.

646826 is a deficient number, since it is larger than the sum of its proper divisors (323416).

646826 is a wasteful number, since it uses less digits than its factorization.

646826 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 323415.

The product of its digits is 13824, while the sum is 32.

The square root of 646826 is about 804.2549347067. The cubic root of 646826 is about 86.4826833368.

The spelling of 646826 in words is "six hundred forty-six thousand, eight hundred twenty-six".