642631 has 12 divisors (see below), whose sum is σ = 727776.
Its totient is φ = 566720.
The previous prime is 642623. The next prime is 642673. The reversal of 642631 is 136246.
Adding to 642631 its reverse (136246), we get a palindrome (778877).
It is not a de Polignac number, because 642631 - 23 = 642623 is a prime.
It is a super-2 number, since 2×6426312 = 825949204322, which contains 22 as substring.
It is a Duffinian number.
It is a nialpdrome in base 15.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (642931) 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 11 ways as a sum of consecutive naturals, for example, 5631 + ... + 5743.
It is an arithmetic number, because the mean of its divisors is an integer number (60648).
2642631 is an apocalyptic number.
642631 is a deficient number, since it is larger than the sum of its proper divisors (85145).
642631 is a wasteful number, since it uses less digits than its factorization.
642631 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 182 (or 171 counting only the distinct ones).
The product of its digits is 864, while the sum is 22.
The square root of 642631 is about 801.6426884841.
The cubic root of 642631 is about 86.2953161011.
The spelling of 642631 in words is "six hundred forty-two thousand, six hundred thirty-one".