642055 has 4 divisors (see below), whose sum is σ = 770472. Its totient is φ = 513640.

The previous prime is 642049. The next prime is 642071. The reversal of 642055 is 550246.

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

It is not a de Polignac number, because 642055 - 2¹¹ = 640007 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64201 + ... + 64210.

It is an arithmetic number, because the mean of its divisors is an integer number (192618).

2⁶⁴²⁰⁵⁵ is an apocalyptic number.

642055 is a deficient number, since it is larger than the sum of its proper divisors (128417).

642055 is a wasteful number, since it uses less digits than its factorization.

642055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128416.

The product of its (nonzero) digits is 1200, while the sum is 22.

The square root of 642055 is about 801.2833456400. The cubic root of 642055 is about 86.2695257900.

Subtracting from 642055 its reverse (550246), we obtain a square (91809 = 303²).

The spelling of 642055 in words is "six hundred forty-two thousand, fifty-five".