99864809 has 6 divisors (see below), whose sum is σ = 109768890. Its totient is φ = 90786080.

The previous prime is 99864797. The next prime is 99864829. The reversal of 99864809 is 90846899.

It can be written as a sum of positive squares in only one way, i.e., 66259600 + 33605209 = 8140^2 + 5797^2 .

It is a de Polignac number, because none of the positive numbers 2^k-99864809 is a prime.

It is a super-3 number, since 3×99864809³ (a number of 25 digits) contains 333 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (99864829) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 412544 + ... + 412785.

It is an arithmetic number, because the mean of its divisors is an integer number (18294815).

Almost surely, 2^99864809 is an apocalyptic number.

It is an amenable number.

99864809 is a deficient number, since it is larger than the sum of its proper divisors (9904081).

99864809 is a wasteful number, since it uses less digits than its factorization.

99864809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 825351 (or 825340 counting only the distinct ones).

The product of its (nonzero) digits is 1119744, while the sum is 53.

The square root of 99864809 is about 9993.2381638786. The cubic root of 99864809 is about 463.9496220201.

The spelling of 99864809 in words is "ninety-nine million, eight hundred sixty-four thousand, eight hundred nine".