9999973 has 2 divisors, whose sum is σ = 9999974.
Its totient is φ = 9999972.
The previous prime is 9999971. The next prime is 9999991. The reversal of 9999973 is 3799999.
It is a weak prime.
It can be written as a sum of positive squares in only one way, i.e., 9941409 + 58564 = 3153^2 + 242^2
It is a cyclic number.
It is not a de Polignac number, because 9999973 - 21 = 9999971 is a prime.
Together with 9999971, 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 (9999971) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (11) of ones.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4999986 + 4999987.
It is an arithmetic number, because the mean of its divisors is an integer number (4999987).
Almost surely, 29999973 is an apocalyptic number.
It is an amenable number.
9999973 is a deficient number, since it is larger than the sum of its proper divisors (1).
9999973 is an equidigital number, since it uses as much as digits as its factorization.
9999973 is an odious number, because the sum of its binary digits is odd.
The product of its digits is 1240029, while the sum is 55.
The square root of 9999973 is about 3162.2733910907.
The cubic root of 9999973 is about 215.4432751039.
The spelling of 9999973 in words is "nine million, nine hundred ninety-nine thousand, nine hundred seventy-three".