646753 has 6 divisors (see below), whose sum is σ = 669282. Its totient is φ = 624960.

The previous prime is 646721. The next prime is 646757. The reversal of 646753 is 357646.

It can be written as a sum of positive squares in only one way, i.e., 508369 + 138384 = 713^2 + 372^2 .

It is not a de Polignac number, because 646753 - 2⁵ = 646721 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (646757) 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 5 ways as a sum of consecutive naturals, for example, 625 + ... + 1297.

It is an arithmetic number, because the mean of its divisors is an integer number (111547).

2⁶⁴⁶⁷⁵³ is an apocalyptic number.

It is an amenable number.

646753 is a deficient number, since it is larger than the sum of its proper divisors (22529).

646753 is an equidigital number, since it uses as much as digits as its factorization.

646753 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 735 (or 704 counting only the distinct ones).

The product of its digits is 15120, while the sum is 31.

The square root of 646753 is about 804.2095498065. The cubic root of 646753 is about 86.4794297707.

The spelling of 646753 in words is "six hundred forty-six thousand, seven hundred fifty-three".