99811121 has 2 divisors, whose sum is σ = 99811122. Its totient is φ = 99811120.

The previous prime is 99811093. The next prime is 99811141. The reversal of 99811121 is 12111899.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 87984400 + 11826721 = 9380^2 + 3439^2 .

It is an emirp because it is prime and its reverse (12111899) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 99811121 - 2²² = 95616817 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (99811141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49905560 + 49905561.

It is an arithmetic number, because the mean of its divisors is an integer number (49905561).

Almost surely, 2^99811121 is an apocalyptic number.

It is an amenable number.

99811121 is a deficient number, since it is larger than the sum of its proper divisors (1).

99811121 is an equidigital number, since it uses as much as digits as its factorization.

99811121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1296, while the sum is 32.

The square root of 99811121 is about 9990.5515863740. The cubic root of 99811121 is about 463.8664662934.

The spelling of 99811121 in words is "ninety-nine million, eight hundred eleven thousand, one hundred twenty-one".