99866021 has 2 divisors, whose sum is σ = 99866022. Its totient is φ = 99866020.

The previous prime is 99866017. The next prime is 99866027. The reversal of 99866021 is 12066899.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 65772100 + 34093921 = 8110^2 + 5839^2 .

It is a cyclic number.

It is not a de Polignac number, because 99866021 - 2² = 99866017 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 99866021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (99866027) 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, 49933010 + 49933011.

It is an arithmetic number, because the mean of its divisors is an integer number (49933011).

Almost surely, 2^99866021 is an apocalyptic number.

It is an amenable number.

99866021 is a deficient number, since it is larger than the sum of its proper divisors (1).

99866021 is an equidigital number, since it uses as much as digits as its factorization.

99866021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 46656, while the sum is 41.

The square root of 99866021 is about 9993.2988046991. The cubic root of 99866021 is about 463.9514989064.

The spelling of 99866021 in words is "ninety-nine million, eight hundred sixty-six thousand, twenty-one".