642256 has 20 divisors (see below), whose sum is σ = 1257732. Its totient is φ = 317696.

The previous prime is 642253. The next prime is 642281. The reversal of 642256 is 652246.

642256 = T₁₃₉ + T₁₄₀ + ... + T₁₈₆.

It can be written as a sum of positive squares in 2 ways, for example, as 512656 + 129600 = 716^2 + 360^2 .

It is a super-3 number, since 3×642256³ = 794777868573339648, which contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 642256.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642253) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2046 + ... + 2338.

2⁶⁴²²⁵⁶ is an apocalyptic number.

It is an amenable number.

642256 is a deficient number, since it is larger than the sum of its proper divisors (615476).

642256 is a wasteful number, since it uses less digits than its factorization.

642256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 438 (or 432 counting only the distinct ones).

The product of its digits is 2880, while the sum is 25.

The square root of 642256 is about 801.4087596227. The cubic root of 642256 is about 86.2785272855.

It can be divided in two parts, 642 and 256, that added together give a palindrome (898).

The spelling of 642256 in words is "six hundred forty-two thousand, two hundred fifty-six".