991274617755 has 12 divisors (see below), whose sum is σ = 1718209337520. Its totient is φ = 528679796112.

The previous prime is 991274617747. The next prime is 991274617789. The reversal of 991274617755 is 557716472199.

991274617755 is a `hidden beast` number, since 9 + 9 + 1 + 2 + 7 + 4 + 617 + 7 + 5 + 5 = 666.

It is not a de Polignac number, because 991274617755 - 2³ = 991274617747 is a prime.

It is a super-2 number, since 2×991274617755² (a number of 25 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 991274617692 and 991274617701.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11014162375 + ... + 11014162464.

It is an arithmetic number, because the mean of its divisors is an integer number (143184111460).

Almost surely, 2^991274617755 is an apocalyptic number.

991274617755 is a deficient number, since it is larger than the sum of its proper divisors (726934719765).

991274617755 is a wasteful number, since it uses less digits than its factorization.

991274617755 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22028324850 (or 22028324847 counting only the distinct ones).

The product of its digits is 33339600, while the sum is 63.

The spelling of 991274617755 in words is "nine hundred ninety-one billion, two hundred seventy-four million, six hundred seventeen thousand, seven hundred fifty-five".