642863 has 4 divisors (see below), whose sum is σ = 692328. Its totient is φ = 593400.

The previous prime is 642853. The next prime is 642869. The reversal of 642863 is 368246.

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 642863 - 2⁶ = 642799 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642869) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24713 + ... + 24738.

It is an arithmetic number, because the mean of its divisors is an integer number (173082).

2⁶⁴²⁸⁶³ is an apocalyptic number.

642863 is a deficient number, since it is larger than the sum of its proper divisors (49465).

642863 is a wasteful number, since it uses less digits than its factorization.

642863 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49464.

The product of its digits is 6912, while the sum is 29.

The square root of 642863 is about 801.7873782993. The cubic root of 642863 is about 86.3056995117.

The spelling of 642863 in words is "six hundred forty-two thousand, eight hundred sixty-three".