9987881 has 2 divisors, whose sum is σ = 9987882. Its totient is φ = 9987880.

The previous prime is 9987877. The next prime is 9987889. The reversal of 9987881 is 1887899.

It is a happy number.

9987881 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9954025 + 33856 = 3155^2 + 184^2 .

It is a cyclic number.

It is not a de Polignac number, because 9987881 - 2² = 9987877 is a prime.

It is a super-2 number, since 2×9987881² = 199515533740322, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (9987889) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4993940 + 4993941.

It is an arithmetic number, because the mean of its divisors is an integer number (4993941).

Almost surely, 2^9987881 is an apocalyptic number.

It is an amenable number.

9987881 is a deficient number, since it is larger than the sum of its proper divisors (1).

9987881 is an equidigital number, since it uses as much as digits as its factorization.

9987881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 290304, while the sum is 50.

The square root of 9987881 is about 3160.3608971129. The cubic root of 9987881 is about 215.3564018415.

The spelling of 9987881 in words is "nine million, nine hundred eighty-seven thousand, eight hundred eighty-one".