1181998791 has 32 divisors (see below), whose sum is σ = 1838611200. Its totient is φ = 749437920.

The previous prime is 1181998787. The next prime is 1181998793. The reversal of 1181998791 is 1978991811.

It is not a de Polignac number, because 1181998791 - 2² = 1181998787 is a prime.

It is a super-2 number, since 2×1181998791² = 2794242283850923362, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1181998793) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 41196 + ... + 63726.

It is an arithmetic number, because the mean of its divisors is an integer number (57456600).

Almost surely, 2^1181998791 is an apocalyptic number.

1181998791 is a deficient number, since it is larger than the sum of its proper divisors (656612409).

1181998791 is a wasteful number, since it uses less digits than its factorization.

1181998791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22636 (or 22630 counting only the distinct ones).

The product of its digits is 326592, while the sum is 54.

The square root of 1181998791 is about 34380.2092925567. The cubic root of 1181998791 is about 1057.3181257565.

The spelling of 1181998791 in words is "one billion, one hundred eighty-one million, nine hundred ninety-eight thousand, seven hundred ninety-one".