99291991 has 2 divisors, whose sum is σ = 99291992. Its totient is φ = 99291990.

The previous prime is 99291971. The next prime is 99292001. The reversal of 99291991 is 19919299.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-99291991 is a prime.

It is a super-3 number, since 3×99291991³ (a number of 25 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 (99291931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49645995 + 49645996.

It is an arithmetic number, because the mean of its divisors is an integer number (49645996).

Almost surely, 2^99291991 is an apocalyptic number.

99291991 is a deficient number, since it is larger than the sum of its proper divisors (1).

99291991 is an equidigital number, since it uses as much as digits as its factorization.

99291991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 118098, while the sum is 49.

The square root of 99291991 is about 9964.5366676028. The cubic root of 99291991 is about 463.0608590097.

The spelling of 99291991 in words is "ninety-nine million, two hundred ninety-one thousand, nine hundred ninety-one".