642281 has 2 divisors, whose sum is σ = 642282. Its totient is φ = 642280.

The previous prime is 642253. The next prime is 642359. The reversal of 642281 is 182246.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 469225 + 173056 = 685^2 + 416^2 .

It is a cyclic number.

It is not a de Polignac number, because 642281 - 2⁶ = 642217 is a prime.

It is a super-2 number, since 2×642281² = 825049765922, which contains 22 as substring.

It is a Chen prime.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 642281.

It is not a weakly prime, because it can be changed into another prime (642211) 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 as a sum of consecutive naturals, namely, 321140 + 321141.

It is an arithmetic number, because the mean of its divisors is an integer number (321141).

2⁶⁴²²⁸¹ is an apocalyptic number.

It is an amenable number.

642281 is a deficient number, since it is larger than the sum of its proper divisors (1).

642281 is an equidigital number, since it uses as much as digits as its factorization.

642281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 768, while the sum is 23.

The square root of 642281 is about 801.4243570045. The cubic root of 642281 is about 86.2796467432.

The spelling of 642281 in words is "six hundred forty-two thousand, two hundred eighty-one".