99280 has 40 divisors (see below), whose sum is σ = 247752. Its totient is φ = 36864.

The previous prime is 99277. The next prime is 99289. The reversal of 99280 is 8299.

It is a happy number.

99280 is nontrivially palindromic in base 9.

It can be written as a sum of positive squares in 4 ways, for example, as 23104 + 76176 = 152^2 + 276^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99289) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1324 + ... + 1396.

2⁹⁹²⁸⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 99280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (123876).

99280 is an abundant number, since it is smaller than the sum of its proper divisors (148472).

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

99280 is a wasteful number, since it uses less digits than its factorization.

99280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103 (or 97 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 28.

The square root of 99280 is about 315.0872894929. The cubic root of 99280 is about 46.3042217740.

Adding to 99280 its product of nonzero digits (1296), we get a triangular number (100576 = T₄₄₈).

The spelling of 99280 in words is "ninety-nine thousand, two hundred eighty".