99781217 has 8 divisors (see below), whose sum is σ = 105417600. Its totient is φ = 94183344.

The previous prime is 99781207. The next prime is 99781229. The reversal of 99781217 is 71218799.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-99781217 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (99781207) 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 in 7 ways as a sum of consecutive naturals, for example, 4217 + ... + 14742.

It is an arithmetic number, because the mean of its divisors is an integer number (13177200).

Almost surely, 2^99781217 is an apocalyptic number.

It is an amenable number.

99781217 is a deficient number, since it is larger than the sum of its proper divisors (5636383).

99781217 is a wasteful number, since it uses less digits than its factorization.

99781217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19255.

The product of its digits is 63504, while the sum is 44.

The square root of 99781217 is about 9989.0548601957. The cubic root of 99781217 is about 463.8201359572.

The spelling of 99781217 in words is "ninety-nine million, seven hundred eighty-one thousand, two hundred seventeen".