99810 has 24 divisors (see below), whose sum is σ = 259740. Its totient is φ = 26592.

The previous prime is 99809. The next prime is 99817. The reversal of 99810 is 1899.

It can be written as a sum of positive squares in 2 ways, for example, as 84681 + 15129 = 291^2 + 123^2 .

It is a super-2 number, since 2×99810² = 19924072200, which contains 22 as substring.

It is a Curzon number.

It is a nialpdrome in base 10.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 99810.

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 11 ways as a sum of consecutive naturals, for example, 465 + ... + 644.

2⁹⁹⁸¹⁰ is an apocalyptic number.

99810 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

99810 is an abundant number, since it is smaller than the sum of its proper divisors (159930).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (129870).

99810 is a wasteful number, since it uses less digits than its factorization.

99810 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1122 (or 1119 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 27.

The square root of 99810 is about 315.9272068056. The cubic root of 99810 is about 46.3864729692.

It can be divided in two parts, 99 and 810, that added together give a palindrome (909).

The spelling of 99810 in words is "ninety-nine thousand, eight hundred ten".