646767 has 24 divisors (see below), whose sum is σ = 1048320. Its totient is φ = 380880.

The previous prime is 646757. The next prime is 646771. The reversal of 646767 is 767646.

646767 is a `hidden beast` number, since 646 + 7 + 6 + 7 = 666.

It is not a de Polignac number, because 646767 - 2¹⁵ = 613999 is a prime.

646767 is a lucky number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 646767.

It is not an unprimeable number, because it can be changed into a prime (646757) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4584 + ... + 4722.

It is an arithmetic number, because the mean of its divisors is an integer number (43680).

2⁶⁴⁶⁷⁶⁷ is an apocalyptic number.

646767 is a deficient number, since it is larger than the sum of its proper divisors (401553).

646767 is a wasteful number, since it uses less digits than its factorization.

646767 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 203 (or 200 counting only the distinct ones).

The product of its digits is 42336, while the sum is 36.

The square root of 646767 is about 804.2182539585. The cubic root of 646767 is about 86.4800537612.

The spelling of 646767 in words is "six hundred forty-six thousand, seven hundred sixty-seven".