42987 has 16 divisors (see below), whose sum is σ = 69120. Its totient is φ = 23232.
The previous prime is 42979. The next prime is 42989. The reversal of 42987 is 78924.
It is not a de Polignac number, because 42987 - 23 = 42979 is a prime.
It is not an unprimeable number, because it can be changed into a prime (42989) 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 15 ways as a sum of consecutive naturals, for example, 439 + ... + 527.
It is an arithmetic number, because the mean of its divisors is an integer number (4320).
242987 is an apocalyptic number.
42987 is a deficient number, since it is larger than the sum of its proper divisors (26133).
42987 is a wasteful number, since it uses less digits than its factorization.
42987 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 122.
The product of its digits is 4032, while the sum is 30.
The square root of 42987 is about 207.3330653803. Note that the first 3 decimals coincide. The cubic root of 42987 is about 35.0304496918.
Subtracting 42987 from its reverse (78924), we obtain a cube (35937 = 333).
The spelling of 42987 in words is "forty-two thousand, nine hundred eighty-seven".
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