987815344321 has 15 divisors (see below), whose sum is σ = 1070312402463. Its totient is φ = 911674501920.

The previous prime is 987815344319. The next prime is 987815344363. The reversal of 987815344321 is 123443518789.

The square root of 987815344321 is 993889.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 7 ways, for example, as 859164001921 + 128651342400 = 926911^2 + 358680^2 .

It is not a de Polignac number, because 987815344321 - 2¹ = 987815344319 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (987815344381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 167964301 + ... + 167970181.

Almost surely, 2^987815344321 is an apocalyptic number.

987815344321 is the 993889-th square number.

987815344321 is the 496945-th centered octagonal number.

It is an amenable number.

987815344321 is a deficient number, since it is larger than the sum of its proper divisors (82497058142).

987815344321 is an frugal number, since it uses more digits than its factorization.

987815344321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11814 (or 5894 counting only the distinct ones).

The product of its digits is 5806080, while the sum is 55.

The spelling of 987815344321 in words is "nine hundred eighty-seven billion, eight hundred fifteen million, three hundred forty-four thousand, three hundred twenty-one".