99281981 has 2 divisors, whose sum is σ = 99281982. Its totient is φ = 99281980.

The previous prime is 99281947. The next prime is 99282019. The reversal of 99281981 is 18918299.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 66161956 + 33120025 = 8134^2 + 5755^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-99281981 is a prime.

It is a super-2 number, since 2×99281981² = 19713823502568722, which contains 22 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 (99281911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49640990 + 49640991.

It is an arithmetic number, because the mean of its divisors is an integer number (49640991).

Almost surely, 2^99281981 is an apocalyptic number.

It is an amenable number.

99281981 is a deficient number, since it is larger than the sum of its proper divisors (1).

99281981 is an equidigital number, since it uses as much as digits as its factorization.

99281981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 93312, while the sum is 47.

The square root of 99281981 is about 9964.0343736862. The cubic root of 99281981 is about 463.0452975164.

The spelling of 99281981 in words is "ninety-nine million, two hundred eighty-one thousand, nine hundred eighty-one".