99999819 has 16 divisors (see below), whose sum is σ = 148308000. Its totient is φ = 66594528.

The previous prime is 99999787. The next prime is 99999821. The reversal of 99999819 is 91899999.

It is not a de Polignac number, because 99999819 - 2⁵ = 99999787 is a prime.

It is a super-2 number, since 2×99999819² = 19999927600065522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (99999839) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 37957 + ... + 40505.

It is an arithmetic number, because the mean of its divisors is an integer number (9269250).

Almost surely, 2^99999819 is an apocalyptic number.

99999819 is a deficient number, since it is larger than the sum of its proper divisors (48308181).

99999819 is a wasteful number, since it uses less digits than its factorization.

99999819 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4011 (or 4005 counting only the distinct ones).

The product of its digits is 4251528, while the sum is 63.

The square root of 99999819 is about 9999.9909499959. The cubic root of 99999819 is about 464.1586033186.

The spelling of 99999819 in words is "ninety-nine million, nine hundred ninety-nine thousand, eight hundred nineteen".