9991975 has 12 divisors (see below), whose sum is σ = 14160304. Its totient is φ = 6851520.

The previous prime is 9991973. The next prime is 9991997. The reversal of 9991975 is 5791999.

9991975 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 9991975 - 2¹ = 9991973 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9991973) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 28374 + ... + 28723.

Almost surely, 2^9991975 is an apocalyptic number.

9991975 is a deficient number, since it is larger than the sum of its proper divisors (4168329).

9991975 is a wasteful number, since it uses less digits than its factorization.

9991975 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57114 (or 57109 counting only the distinct ones).

The product of its digits is 229635, while the sum is 49.

The square root of 9991975 is about 3161.0085415892. The cubic root of 9991975 is about 215.3858224520.

The spelling of 9991975 in words is "nine million, nine hundred ninety-one thousand, nine hundred seventy-five".