642331 has 4 divisors (see below), whose sum is σ = 644112. Its totient is φ = 640552.

The previous prime is 642281. The next prime is 642359. The reversal of 642331 is 133246.

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 642331 - 2⁹ = 641819 is a prime.

It is a super-3 number, since 3×642331³ = 795056333708252073, which contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 642299 and 642308.

It is not an unprimeable number, because it can be changed into a prime (642361) 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 3 ways as a sum of consecutive naturals, for example, 136 + ... + 1141.

It is an arithmetic number, because the mean of its divisors is an integer number (161028).

2⁶⁴²³³¹ is an apocalyptic number.

642331 is a deficient number, since it is larger than the sum of its proper divisors (1781).

642331 is a wasteful number, since it uses less digits than its factorization.

642331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1780.

The product of its digits is 432, while the sum is 19.

The square root of 642331 is about 801.4555508573. The cubic root of 642331 is about 86.2818855713.

Adding to 642331 its reverse (133246), we get a palindrome (775577).

The spelling of 642331 in words is "six hundred forty-two thousand, three hundred thirty-one".