99973 has 4 divisors (see below), whose sum is σ = 100620. Its totient is φ = 99328.

The previous prime is 99971. The next prime is 99989. The reversal of 99973 is 37999.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 68644 + 31329 = 262^2 + 177^2 .

It is a cyclic number.

It is not a de Polignac number, because 99973 - 2¹ = 99971 is a prime.

It is a Duffinian number.

99973 is a lucky number.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99971) 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 3 ways as a sum of consecutive naturals, for example, 63 + ... + 451.

It is an arithmetic number, because the mean of its divisors is an integer number (25155).

2⁹⁹⁹⁷³ is an apocalyptic number.

It is an amenable number.

99973 is a deficient number, since it is larger than the sum of its proper divisors (647).

99973 is a wasteful number, since it uses less digits than its factorization.

99973 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 646.

The product of its digits is 15309, while the sum is 37.

The square root of 99973 is about 316.1850723864. The cubic root of 99973 is about 46.4117105302.

It can be divided in two parts, 9997 and 3, that added together give a 4-th power (10000 = 10⁴).

The spelling of 99973 in words is "ninety-nine thousand, nine hundred seventy-three".