99996821 has 2 divisors, whose sum is σ = 99996822. Its totient is φ = 99996820.

The previous prime is 99996803. The next prime is 99996833. The reversal of 99996821 is 12869999.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 98227921 + 1768900 = 9911^2 + 1330^2 .

It is a cyclic number.

It is not a de Polignac number, because 99996821 - 2¹⁴ = 99980437 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (99996121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49998410 + 49998411.

It is an arithmetic number, because the mean of its divisors is an integer number (49998411).

Almost surely, 2^99996821 is an apocalyptic number.

It is an amenable number.

99996821 is a deficient number, since it is larger than the sum of its proper divisors (1).

99996821 is an equidigital number, since it uses as much as digits as its factorization.

99996821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 629856, while the sum is 53.

The square root of 99996821 is about 9999.8410487367. The cubic root of 99996821 is about 464.1539647722.

The spelling of 99996821 in words is "ninety-nine million, nine hundred ninety-six thousand, eight hundred twenty-one".