99865221 has 8 divisors (see below), whose sum is σ = 136250400. Its totient is φ = 65028432.

The previous prime is 99865211. The next prime is 99865223. The reversal of 99865221 is 12256899.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 99865221 - 2⁵ = 99865189 is a prime.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99865223) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 386946 + ... + 387203.

It is an arithmetic number, because the mean of its divisors is an integer number (17031300).

Almost surely, 2^99865221 is an apocalyptic number.

It is an amenable number.

99865221 is a deficient number, since it is larger than the sum of its proper divisors (36385179).

99865221 is a wasteful number, since it uses less digits than its factorization.

99865221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 774195.

The product of its digits is 77760, while the sum is 42.

The square root of 99865221 is about 9993.2587777962. The cubic root of 99865221 is about 463.9502600392.

The spelling of 99865221 in words is "ninety-nine million, eight hundred sixty-five thousand, two hundred twenty-one".