987980320339991 has 4 divisors (see below), whose sum is σ = 1077796713098184. Its totient is φ = 898163927581800.

The previous prime is 987980320339967. The next prime is 987980320340009. The reversal of 987980320339991 is 199933023089789.

It is a semiprime because it is the product of two primes.

It is a de Polignac number, because none of the positive numbers 2^k-987980320339991 is a prime.

It is a super-2 number, since 2×987980320339991² (a number of 31 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (987980320339091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 44908196379080 + ... + 44908196379101.

It is an arithmetic number, because the mean of its divisors is an integer number (269449178274546).

Almost surely, 2^{987980320339991} is an apocalyptic number.

987980320339991 is a deficient number, since it is larger than the sum of its proper divisors (89816392758193).

987980320339991 is a wasteful number, since it uses less digits than its factorization.

987980320339991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89816392758192.

The product of its (nonzero) digits is 1428513408, while the sum is 80.

The spelling of 987980320339991 in words is "nine hundred eighty-seven trillion, nine hundred eighty billion, three hundred twenty million, three hundred thirty-nine thousand, nine hundred ninety-one".