9891251 has 2 divisors, whose sum is σ = 9891252. Its totient is φ = 9891250.

The previous prime is 9891241. The next prime is 9891253. The reversal of 9891251 is 1521989.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 9891251 - 2¹⁸ = 9629107 is a prime.

Together with 9891253, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (9891253) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4945625 + 4945626.

It is an arithmetic number, because the mean of its divisors is an integer number (4945626).

Almost surely, 2^9891251 is an apocalyptic number.

9891251 is a deficient number, since it is larger than the sum of its proper divisors (1).

9891251 is an equidigital number, since it uses as much as digits as its factorization.

9891251 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6480, while the sum is 35.

The square root of 9891251 is about 3145.0359298425. The cubic root of 9891251 is about 214.6596453709.

The spelling of 9891251 in words is "nine million, eight hundred ninety-one thousand, two hundred fifty-one".