9891257 has 2 divisors, whose sum is σ = 9891258. Its totient is φ = 9891256.

The previous prime is 9891253. The next prime is 9891289. The reversal of 9891257 is 7521989.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6446521 + 3444736 = 2539^2 + 1856^2 .

It is a cyclic number.

It is not a de Polignac number, because 9891257 - 2² = 9891253 is a prime.

It is not a weakly prime, because it can be changed into another prime (9891251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4945628 + 4945629.

It is an arithmetic number, because the mean of its divisors is an integer number (4945629).

Almost surely, 2^9891257 is an apocalyptic number.

It is an amenable number.

9891257 is a deficient number, since it is larger than the sum of its proper divisors (1).

9891257 is an equidigital number, since it uses as much as digits as its factorization.

9891257 is an odious number, because the sum of its binary digits is odd.

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

The square root of 9891257 is about 3145.0368837265. The cubic root of 9891257 is about 214.6596887748.

The spelling of 9891257 in words is "nine million, eight hundred ninety-one thousand, two hundred fifty-seven".