646257 has 8 divisors (see below), whose sum is σ = 889600. Its totient is φ = 416880.

The previous prime is 646253. The next prime is 646259. The reversal of 646257 is 752646.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 646257 - 2² = 646253 is a prime.

It is a super-2 number, since 2×646257² = 835296220098, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (646253) 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 7 ways as a sum of consecutive naturals, for example, 3382 + ... + 3567.

It is an arithmetic number, because the mean of its divisors is an integer number (111200).

2⁶⁴⁶²⁵⁷ is an apocalyptic number.

It is an amenable number.

646257 is a deficient number, since it is larger than the sum of its proper divisors (243343).

646257 is a wasteful number, since it uses less digits than its factorization.

646257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6983.

The product of its digits is 10080, while the sum is 30.

The square root of 646257 is about 803.9011133218. The cubic root of 646257 is about 86.4573168636.

It can be divided in two parts, 646 and 257, that added together give a triangular number (903 = T₄₂).

The spelling of 646257 in words is "six hundred forty-six thousand, two hundred fifty-seven".