642542 has 16 divisors (see below), whose sum is σ = 1044240. Its totient is φ = 295488.

The previous prime is 642533. The next prime is 642547. The reversal of 642542 is 245246.

It is a plaindrome in base 16.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 642542.

It is not an unprimeable number, because it can be changed into a prime (642547) by changing a digit.

642542 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 7 ways as a sum of consecutive naturals, for example, 1178 + ... + 1634.

It is an arithmetic number, because the mean of its divisors is an integer number (65265).

2⁶⁴²⁵⁴² is an apocalyptic number.

642542 is a deficient number, since it is larger than the sum of its proper divisors (401698).

642542 is a wasteful number, since it uses less digits than its factorization.

642542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 515.

The product of its digits is 1920, while the sum is 23.

The square root of 642542 is about 801.5871755461. The cubic root of 642542 is about 86.2913321468.

Adding to 642542 its reverse (245246), we get a palindrome (887788).

The spelling of 642542 in words is "six hundred forty-two thousand, five hundred forty-two".