642135 has 32 divisors (see below), whose sum is σ = 1149120. Its totient is φ = 304128.

The previous prime is 642133. The next prime is 642149. The reversal of 642135 is 531246.

It is a happy number.

It is not a de Polignac number, because 642135 - 2¹ = 642133 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642133) 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 31 ways as a sum of consecutive naturals, for example, 7171 + ... + 7259.

It is an arithmetic number, because the mean of its divisors is an integer number (35910).

2⁶⁴²¹³⁵ is an apocalyptic number.

642135 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

642135 is a deficient number, since it is larger than the sum of its proper divisors (506985).

642135 is a wasteful number, since it uses less digits than its factorization.

642135 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 147.

The product of its digits is 720, while the sum is 21.

The square root of 642135 is about 801.3332640044. Note that the first 3 decimals coincide. The cubic root of 642135 is about 86.2731086998.

Subtracting from 642135 its reverse (531246), we obtain a square (110889 = 333²).

It can be divided in two parts, 642 and 135, that added together give a palindrome (777).

The spelling of 642135 in words is "six hundred forty-two thousand, one hundred thirty-five".