642259 has 4 divisors (see below), whose sum is σ = 648720. Its totient is φ = 635800.

The previous prime is 642253. The next prime is 642281. The reversal of 642259 is 952246.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 642259 - 2⁹ = 641747 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (642253) 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 3 ways as a sum of consecutive naturals, for example, 3079 + ... + 3280.

It is an arithmetic number, because the mean of its divisors is an integer number (162180).

2⁶⁴²²⁵⁹ is an apocalyptic number.

642259 is a deficient number, since it is larger than the sum of its proper divisors (6461).

642259 is a wasteful number, since it uses less digits than its factorization.

642259 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6460.

The product of its digits is 4320, while the sum is 28.

The square root of 642259 is about 801.4106313245. The cubic root of 642259 is about 86.2786616220.

The spelling of 642259 in words is "six hundred forty-two thousand, two hundred fifty-nine".