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BaseRepresentation
bin11111000011
32201121
4133003
530422
613111
75536
oct3703
92647
101987
111547
121197
13b9b
14a1d
158c7
hex7c3

1987 has 2 divisors, whose sum is σ = 1988. Its totient is φ = 1986.

The previous prime is 1979. The next prime is 1993. The reversal of 1987 is 7891.

1987 is nontrivially palindromic in base 13.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1987 - 23 = 1979 is a prime.

1987 is an undulating number in base 13.

1987 is a lucky number.

It is a zygodrome in base 2.

It is not a weakly prime, because it can be changed into another prime (1907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 993 + 994.

It is an arithmetic number, because the mean of its divisors is an integer number (994).

21987 is an apocalyptic number.

1987 is a deficient number, since it is larger than the sum of its proper divisors (1).

1987 is an equidigital number, since it uses as much as digits as its factorization.

1987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 504, while the sum is 25.

The square root of 1987 is about 44.5757781760. The cubic root of 1987 is about 12.5718528487.

It can be divided in two parts, 19 and 87, that multiplied together give a triangular number (1653 = T57).

The spelling of 1987 in words is "one thousand, nine hundred eighty-seven".