99813 has 16 divisors (see below), whose sum is σ = 156800. Its totient is φ = 56448.

The previous prime is 99809. The next prime is 99817. The reversal of 99813 is 31899.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (99809) and next prime (99817).

It is not a de Polignac number, because 99813 - 2² = 99809 is a prime.

99813 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99817) 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, 981 + ... + 1077.

It is an arithmetic number, because the mean of its divisors is an integer number (9800).

2⁹⁹⁸¹³ is an apocalyptic number.

It is an amenable number.

99813 is a deficient number, since it is larger than the sum of its proper divisors (56987).

99813 is an equidigital number, since it uses as much as digits as its factorization.

99813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 121 (or 107 counting only the distinct ones).

The product of its digits is 1944, while the sum is 30.

The square root of 99813 is about 315.9319546991. The cubic root of 99813 is about 46.3869377123.

The spelling of 99813 in words is "ninety-nine thousand, eight hundred thirteen".