9991151 has 2 divisors, whose sum is σ = 9991152. Its totient is φ = 9991150.

The previous prime is 9991141. The next prime is 9991159. The reversal of 9991151 is 1511999.

It is a strong prime.

It is an emirp because it is prime and its reverse (1511999) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9991151 is a prime.

It is a super-3 number, since 3×9991151³ (a number of 22 digits) contains 333 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9991159) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4995575 + 4995576.

It is an arithmetic number, because the mean of its divisors is an integer number (4995576).

Almost surely, 2^9991151 is an apocalyptic number.

9991151 is a deficient number, since it is larger than the sum of its proper divisors (1).

9991151 is an equidigital number, since it uses as much as digits as its factorization.

9991151 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3645, while the sum is 35.

The square root of 9991151 is about 3160.8782007537. The cubic root of 9991151 is about 215.3799016073.

The spelling of 9991151 in words is "nine million, nine hundred ninety-one thousand, one hundred fifty-one".