99945221 has 2 divisors, whose sum is σ = 99945222. Its totient is φ = 99945220.

The previous prime is 99945217. The next prime is 99945247. The reversal of 99945221 is 12254999.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 98704225 + 1240996 = 9935^2 + 1114^2 .

It is a cyclic number.

It is not a de Polignac number, because 99945221 - 2² = 99945217 is a prime.

It is a Sophie Germain 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 (99945421) 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, 49972610 + 49972611.

It is an arithmetic number, because the mean of its divisors is an integer number (49972611).

Almost surely, 2^99945221 is an apocalyptic number.

It is an amenable number.

99945221 is a deficient number, since it is larger than the sum of its proper divisors (1).

99945221 is an equidigital number, since it uses as much as digits as its factorization.

99945221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 58320, while the sum is 41.

The square root of 99945221 is about 9997.2606748049. The cubic root of 99945221 is about 464.0741140159.

The spelling of 99945221 in words is "ninety-nine million, nine hundred forty-five thousand, two hundred twenty-one".