99784 has 8 divisors (see below), whose sum is σ = 187110. Its totient is φ = 49888.

The previous prime is 99767. The next prime is 99787. The reversal of 99784 is 48799.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 77284 + 22500 = 278^2 + 150^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (99787) by changing a digit.

99784 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 as a sum of consecutive naturals, namely, 6229 + ... + 6244.

2⁹⁹⁷⁸⁴ is an apocalyptic number.

It is an amenable number.

99784 is a deficient number, since it is larger than the sum of its proper divisors (87326).

99784 is a wasteful number, since it uses less digits than its factorization.

99784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12479 (or 12475 counting only the distinct ones).

The product of its digits is 18144, while the sum is 37.

The square root of 99784 is about 315.8860554061. The cubic root of 99784 is about 46.3824448056.

It can be divided in two parts, 997 and 84, that added together give a triangular number (1081 = T₄₆).

The spelling of 99784 in words is "ninety-nine thousand, seven hundred eighty-four".