1179943991 has 4 divisors (see below), whose sum is σ = 1180401984. Its totient is φ = 1179486000.

The previous prime is 1179943969. The next prime is 1179943997. The reversal of 1179943991 is 1993499711.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1993499711 = 7 ⋅284785673.

It is a cyclic number.

It is not a de Polignac number, because 1179943991 - 2⁶ = 1179943927 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 (1179943997) 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 3 ways as a sum of consecutive naturals, for example, 225110 + ... + 230291.

It is an arithmetic number, because the mean of its divisors is an integer number (295100496).

Almost surely, 2^1179943991 is an apocalyptic number.

1179943991 is a deficient number, since it is larger than the sum of its proper divisors (457993).

1179943991 is an equidigital number, since it uses as much as digits as its factorization.

1179943991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 457992.

The product of its digits is 551124, while the sum is 53.

The square root of 1179943991 is about 34350.3128224475. The cubic root of 1179943991 is about 1056.7050858045.

The spelling of 1179943991 in words is "one billion, one hundred seventy-nine million, nine hundred forty-three thousand, nine hundred ninety-one".