8821091989 has 2 divisors, whose sum is σ = 8821091990. Its totient is φ = 8821091988.

The previous prime is 8821091987. The next prime is 8821092013. The reversal of 8821091989 is 9891901288.

8821091989 is digitally balanced in base 2, 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., 8060987089 + 760104900 = 89783^2 + 27570^2 .

It is a cyclic number.

It is not a de Polignac number, because 8821091989 - 2¹ = 8821091987 is a prime.

It is a super-2 number, since 2×8821091989² (a number of 21 digits) contains 22 as substring.

Together with 8821091987, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8821091987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4410545994 + 4410545995.

It is an arithmetic number, because the mean of its divisors is an integer number (4410545995).

Almost surely, 2^8821091989 is an apocalyptic number.

It is an amenable number.

8821091989 is a deficient number, since it is larger than the sum of its proper divisors (1).

8821091989 is an equidigital number, since it uses as much as digits as its factorization.

8821091989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 746496, while the sum is 55.

The square root of 8821091989 is about 93920.6685932335. The cubic root of 8821091989 is about 2066.2083724881.

The spelling of 8821091989 in words is "eight billion, eight hundred twenty-one million, ninety-one thousand, nine hundred eighty-nine".