99999817 has 8 divisors (see below), whose sum is σ = 102322440. Its totient is φ = 97693440.

The previous prime is 99999787. The next prime is 99999821. The reversal of 99999817 is 71899999.

It can be written as a sum of positive squares in 4 ways, for example, as 17480761 + 82519056 = 4181^2 + 9084^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 99999817 - 2¹¹ = 99997769 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (99999827) 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, 8859 + ... + 16687.

It is an arithmetic number, because the mean of its divisors is an integer number (12790305).

Almost surely, 2^99999817 is an apocalyptic number.

It is an amenable number.

99999817 is a deficient number, since it is larger than the sum of its proper divisors (2322623).

99999817 is a wasteful number, since it uses less digits than its factorization.

99999817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8123.

The product of its digits is 3306744, while the sum is 61.

The square root of 99999817 is about 9999.9908499958. The cubic root of 99999817 is about 464.1586002242.

The spelling of 99999817 in words is "ninety-nine million, nine hundred ninety-nine thousand, eight hundred seventeen".