991746386775 has 36 divisors (see below), whose sum is σ = 1776536372520. Its totient is φ = 528869352000.

The previous prime is 991746386713. The next prime is 991746386789. The reversal of 991746386775 is 577683647199.

It is a happy number.

991746386775 is a `hidden beast` number, since 9 + 9 + 17 + 463 + 86 + 7 + 75 = 666.

It is not a de Polignac number, because 991746386775 - 2¹⁶ = 991746321239 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1696300 + ... + 2204750.

It is an arithmetic number, because the mean of its divisors is an integer number (49348232570).

Almost surely, 2^991746386775 is an apocalyptic number.

991746386775 is a deficient number, since it is larger than the sum of its proper divisors (784789985745).

991746386775 is a wasteful number, since it uses less digits than its factorization.

991746386775 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 517136 (or 517128 counting only the distinct ones).

The product of its digits is 480090240, while the sum is 72.

The spelling of 991746386775 in words is "nine hundred ninety-one billion, seven hundred forty-six million, three hundred eighty-six thousand, seven hundred seventy-five".