987543209 has 12 divisors (see below), whose sum is σ = 1074683484. Its totient is φ = 904310784.

The previous prime is 987543187. The next prime is 987543211. The reversal of 987543209 is 902345789.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 350737984 + 636805225 = 18728^2 + 25235^2 .

It is a de Polignac number, because none of the positive numbers 2^k-987543209 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (987543509) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2057 + ... + 44489.

It is an arithmetic number, because the mean of its divisors is an integer number (89556957).

Almost surely, 2^987543209 is an apocalyptic number.

It is an amenable number.

987543209 is a deficient number, since it is larger than the sum of its proper divisors (87140275).

987543209 is a wasteful number, since it uses less digits than its factorization.

987543209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42524 (or 42487 counting only the distinct ones).

The product of its (nonzero) digits is 544320, while the sum is 47.

The square root of 987543209 is about 31425.2002221147. The cubic root of 987543209 is about 995.8303747224.

The spelling of 987543209 in words is "nine hundred eighty-seven million, five hundred forty-three thousand, two hundred nine".