99999999999973 has 2 divisors, whose sum is σ = 99999999999974. Its totient is φ = 99999999999972.

The previous prime is 99999999999971. The next prime is 100000000000031. The reversal of 99999999999973 is 37999999999999.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 99722732460129 + 277267539844 = 9986127^2 + 526562^2 .

It is a cyclic number.

It is not a de Polignac number, because 99999999999973 - 2¹ = 99999999999971 is a prime.

It is a super-9 number, since 9×99999999999973⁹ (a number of 127 digits) contains 999999999 as substring.

Together with 99999999999971, it forms a pair of twin primes.

It is a nialpdrome in base 10.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (99999999999971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49999999999986 + 49999999999987.

It is an arithmetic number, because the mean of its divisors is an integer number (49999999999987).

Almost surely, 2^{99999999999973} is an apocalyptic number.

It is an amenable number.

99999999999973 is a deficient number, since it is larger than the sum of its proper divisors (1).

99999999999973 is an equidigital number, since it uses as much as digits as its factorization.

99999999999973 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5931020266101, while the sum is 118.

It can be divided in two parts, 9999999999997 and 3, that added together give a 13-th power (10000000000000 = 10¹³).

The spelling of 99999999999973 in words is "ninety-nine trillion, nine hundred ninety-nine billion, nine hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred seventy-three".