646477 has 6 divisors (see below), whose sum is σ = 699342. Its totient is φ = 594072.

The previous prime is 646453. The next prime is 646519. The reversal of 646477 is 774646.

It can be written as a sum of positive squares in only one way, i.e., 447561 + 198916 = 669^2 + 446^2 .

It is a de Polignac number, because none of the positive numbers 2^k-646477 is a prime.

It is a Duffinian number.

646477 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646577) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2788 + ... + 3010.

It is an arithmetic number, because the mean of its divisors is an integer number (116557).

2⁶⁴⁶⁴⁷⁷ is an apocalyptic number.

It is an amenable number.

646477 is a deficient number, since it is larger than the sum of its proper divisors (52865).

646477 is an equidigital number, since it uses as much as digits as its factorization.

646477 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 459 (or 236 counting only the distinct ones).

The product of its digits is 28224, while the sum is 34.

The square root of 646477 is about 804.0379344285. The cubic root of 646477 is about 86.4671264036.

The spelling of 646477 in words is "six hundred forty-six thousand, four hundred seventy-seven".