99888221 has 2 divisors, whose sum is σ = 99888222. Its totient is φ = 99888220.

The previous prime is 99888203. The next prime is 99888227. The reversal of 99888221 is 12288899.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 95844100 + 4044121 = 9790^2 + 2011^2 .

It is a cyclic number.

It is not a de Polignac number, because 99888221 - 2⁶ = 99888157 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a nialpdrome in base 10.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (99888227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49944110 + 49944111.

It is an arithmetic number, because the mean of its divisors is an integer number (49944111).

Almost surely, 2^99888221 is an apocalyptic number.

It is an amenable number.

99888221 is a deficient number, since it is larger than the sum of its proper divisors (1).

99888221 is an equidigital number, since it uses as much as digits as its factorization.

99888221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 165888, while the sum is 47.

The square root of 99888221 is about 9994.4094873084. The cubic root of 99888221 is about 463.9858748301.

The spelling of 99888221 in words is "ninety-nine million, eight hundred eighty-eight thousand, two hundred twenty-one".