1187105813 has 4 divisors (see below), whose sum is σ = 1187175948. Its totient is φ = 1187035680.

The previous prime is 1187105809. The next prime is 1187105849. The reversal of 1187105813 is 3185017811.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 3185017811 = 8017 ⋅397283.

It can be written as a sum of positive squares in 2 ways, for example, as 258502084 + 928603729 = 16078^2 + 30473^2 .

It is a cyclic number.

It is not a de Polignac number, because 1187105813 - 2² = 1187105809 is a prime.

It is a super-2 number, since 2×1187105813² = 2818440422516781938, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1187105863) 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, 7745 + ... + 49337.

It is an arithmetic number, because the mean of its divisors is an integer number (296793987).

Almost surely, 2^1187105813 is an apocalyptic number.

It is an amenable number.

1187105813 is a deficient number, since it is larger than the sum of its proper divisors (70135).

1187105813 is an equidigital number, since it uses as much as digits as its factorization.

1187105813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70134.

The product of its (nonzero) digits is 6720, while the sum is 35.

The square root of 1187105813 is about 34454.4019393749. The cubic root of 1187105813 is about 1058.8387107040.

The spelling of 1187105813 in words is "one billion, one hundred eighty-seven million, one hundred five thousand, eight hundred thirteen".