99897881 has 2 divisors, whose sum is σ = 99897882. Its totient is φ = 99897880.

The previous prime is 99897773. The next prime is 99897883. The reversal of 99897881 is 18879899.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 74304400 + 25593481 = 8620^2 + 5059^2 .

It is a cyclic number.

It is not a de Polignac number, because 99897881 - 2²² = 95703577 is a prime.

It is a super-2 number, since 2×99897881² = 19959173256580322, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 99897883, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 99897881.

It is not a weakly prime, because it can be changed into another prime (99897883) 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, 49948940 + 49948941.

It is an arithmetic number, because the mean of its divisors is an integer number (49948941).

Almost surely, 2^99897881 is an apocalyptic number.

It is an amenable number.

99897881 is a deficient number, since it is larger than the sum of its proper divisors (1).

99897881 is an equidigital number, since it uses as much as digits as its factorization.

99897881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2612736, while the sum is 59.

The square root of 99897881 is about 9994.8927457977. The cubic root of 99897881 is about 464.0008314120. Note that the first 3 decimals are identical.

The spelling of 99897881 in words is "ninety-nine million, eight hundred ninety-seven thousand, eight hundred eighty-one".