642559 has 4 divisors (see below), whose sum is σ = 644904. Its totient is φ = 640216.

The previous prime is 642557. The next prime is 642563. The reversal of 642559 is 955246.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 955246 = 2 ⋅477623.

It is a cyclic number.

It is not a de Polignac number, because 642559 - 2¹ = 642557 is a prime.

It is a d-powerful number, because it can be written as 6² + 4³ + 5³ + 2¹⁵ + 5⁷ + 9⁶ .

It is a Duffinian number.

It is a plaindrome in base 8 and base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 642559.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642557) 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, 697 + ... + 1330.

It is an arithmetic number, because the mean of its divisors is an integer number (161226).

2⁶⁴²⁵⁵⁹ is an apocalyptic number.

642559 is a deficient number, since it is larger than the sum of its proper divisors (2345).

642559 is a wasteful number, since it uses less digits than its factorization.

642559 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2344.

The product of its digits is 10800, while the sum is 31.

The square root of 642559 is about 801.5977794380. The cubic root of 642559 is about 86.2920931553.

The spelling of 642559 in words is "six hundred forty-two thousand, five hundred fifty-nine".