987643 has 6 divisors (see below), whose sum is σ = 1033004. Its totient is φ = 944196.

The previous prime is 987631. The next prime is 987659. The reversal of 987643 is 346789.

It is not a de Polignac number, because 987643 - 2¹⁷ = 856571 is a prime.

It is an Ulam number.

It is a Duffinian number.

987643 is a lucky number.

It is a nialpdrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (987043) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 405 + ... + 1462.

2⁹⁸⁷⁶⁴³ is an apocalyptic number.

987643 is a deficient number, since it is larger than the sum of its proper divisors (45361).

987643 is a wasteful number, since it uses less digits than its factorization.

987643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1913 (or 1890 counting only the distinct ones).

The product of its digits is 36288, while the sum is 37.

The square root of 987643 is about 993.8022942215. The cubic root of 987643 is about 99.5863916398.

The spelling of 987643 in words is "nine hundred eighty-seven thousand, six hundred forty-three".