646069 has 4 divisors (see below), whose sum is σ = 648000. Its totient is φ = 644140.

The previous prime is 646067. The next prime is 646073. The reversal of 646069 is 960646.

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 646069 - 2¹ = 646067 is a prime.

It is a super-2 number, since 2×646069² = 834810305522, which contains 22 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

646069 is a lucky number.

It is a nialpdrome in base 15.

It is a self number, because there is not a number n which added to its sum of digits gives 646069.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646067) 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, 319 + ... + 1180.

It is an arithmetic number, because the mean of its divisors is an integer number (162000).

2⁶⁴⁶⁰⁶⁹ is an apocalyptic number.

It is an amenable number.

646069 is a deficient number, since it is larger than the sum of its proper divisors (1931).

646069 is a wasteful number, since it uses less digits than its factorization.

646069 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1930.

The product of its (nonzero) digits is 7776, while the sum is 31.

The square root of 646069 is about 803.7841750122. The cubic root of 646069 is about 86.4489324015.

The spelling of 646069 in words is "six hundred forty-six thousand, sixty-nine".