9891000257 has 2 divisors, whose sum is σ = 9891000258. Its totient is φ = 9891000256.

The previous prime is 9891000253. The next prime is 9891000277. The reversal of 9891000257 is 7520001989.

9891000257 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., 7811731456 + 2079268801 = 88384^2 + 45599^2 .

It is a cyclic number.

It is not a de Polignac number, because 9891000257 - 2² = 9891000253 is a prime.

It is not a weakly prime, because it can be changed into another prime (9891000253) 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, 4945500128 + 4945500129.

It is an arithmetic number, because the mean of its divisors is an integer number (4945500129).

Almost surely, 2^9891000257 is an apocalyptic number.

It is an amenable number.

9891000257 is a deficient number, since it is larger than the sum of its proper divisors (1).

9891000257 is an equidigital number, since it uses as much as digits as its factorization.

9891000257 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 45360, while the sum is 41.

The square root of 9891000257 is about 99453.5080175657. The cubic root of 9891000257 is about 2146.5783148308.

The spelling of 9891000257 in words is "nine billion, eight hundred ninety-one million, two hundred fifty-seven", and thus it is an aban number.