9981881387 has 2 divisors, whose sum is σ = 9981881388. Its totient is φ = 9981881386.

The previous prime is 9981881383. The next prime is 9981881407. The reversal of 9981881387 is 7831881899.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 9981881387 - 2² = 9981881383 is a prime.

It is not a weakly prime, because it can be changed into another prime (9981881383) 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 as a sum of consecutive naturals, namely, 4990940693 + 4990940694.

It is an arithmetic number, because the mean of its divisors is an integer number (4990940694).

Almost surely, 2^9981881387 is an apocalyptic number.

9981881387 is a deficient number, since it is larger than the sum of its proper divisors (1).

9981881387 is an equidigital number, since it uses as much as digits as its factorization.

9981881387 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6967296, while the sum is 62.

The square root of 9981881387 is about 99909.3658622654. The cubic root of 9981881387 is about 2153.1327244419.

The spelling of 9981881387 in words is "nine billion, nine hundred eighty-one million, eight hundred eighty-one thousand, three hundred eighty-seven".