9861906389 has 2 divisors, whose sum is σ = 9861906390. Its totient is φ = 9861906388.

The previous prime is 9861906361. The next prime is 9861906391. The reversal of 9861906389 is 9836091689.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5527922500 + 4333983889 = 74350^2 + 65833^2 .

It is a cyclic number.

It is not a de Polignac number, because 9861906389 - 2¹² = 9861902293 is a prime.

Together with 9861906391, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9861908389) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4930953194 + 4930953195.

It is an arithmetic number, because the mean of its divisors is an integer number (4930953195).

Almost surely, 2^9861906389 is an apocalyptic number.

It is an amenable number.

9861906389 is a deficient number, since it is larger than the sum of its proper divisors (1).

9861906389 is an equidigital number, since it uses as much as digits as its factorization.

9861906389 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5038848, while the sum is 59.

The square root of 9861906389 is about 99307.1316119844. The cubic root of 9861906389 is about 2144.4715646487.

The spelling of 9861906389 in words is "nine billion, eight hundred sixty-one million, nine hundred six thousand, three hundred eighty-nine".