99697181 has 2 divisors, whose sum is σ = 99697182. Its totient is φ = 99697180.

The previous prime is 99697151. The next prime is 99697183. The reversal of 99697181 is 18179699.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 93296281 + 6400900 = 9659^2 + 2530^2 .

It is an emirp because it is prime and its reverse (18179699) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-99697181 is a prime.

It is a super-2 number, since 2×99697181² = 19879055798693522, which contains 22 as substring.

Together with 99697183, 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 (99697183) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49848590 + 49848591.

It is an arithmetic number, because the mean of its divisors is an integer number (49848591).

Almost surely, 2^99697181 is an apocalyptic number.

It is an amenable number.

99697181 is a deficient number, since it is larger than the sum of its proper divisors (1).

99697181 is an equidigital number, since it uses as much as digits as its factorization.

99697181 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 244944, while the sum is 50.

The square root of 99697181 is about 9984.8475701935. The cubic root of 99697181 is about 463.6898892114.

The spelling of 99697181 in words is "ninety-nine million, six hundred ninety-seven thousand, one hundred eighty-one".