642853 has 2 divisors, whose sum is σ = 642854. Its totient is φ = 642852.

The previous prime is 642833. The next prime is 642869. The reversal of 642853 is 358246.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 611524 + 31329 = 782^2 + 177^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-642853 is a prime.

642853 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (642833) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321426 + 321427.

It is an arithmetic number, because the mean of its divisors is an integer number (321427).

2⁶⁴²⁸⁵³ is an apocalyptic number.

It is an amenable number.

642853 is a deficient number, since it is larger than the sum of its proper divisors (1).

642853 is an equidigital number, since it uses as much as digits as its factorization.

642853 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5760, while the sum is 28.

The square root of 642853 is about 801.7811422078. The cubic root of 642853 is about 86.3052520025.

The spelling of 642853 in words is "six hundred forty-two thousand, eight hundred fifty-three".