1186741561 has 4 divisors (see below), whose sum is σ = 1186814592. Its totient is φ = 1186668532.

The previous prime is 1186741547. The next prime is 1186741583. The reversal of 1186741561 is 1651476811.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1651476811 = 269 ⋅6139319.

It is a cyclic number.

It is not a de Polignac number, because 1186741561 - 2¹¹ = 1186739513 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1186741541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 96 + ... + 48718.

It is an arithmetic number, because the mean of its divisors is an integer number (296703648).

Almost surely, 2^1186741561 is an apocalyptic number.

It is an amenable number.

1186741561 is a deficient number, since it is larger than the sum of its proper divisors (73031).

1186741561 is an equidigital number, since it uses as much as digits as its factorization.

1186741561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73030.

The product of its digits is 40320, while the sum is 40.

The square root of 1186741561 is about 34449.1155329132. The cubic root of 1186741561 is about 1058.7304014675.

The spelling of 1186741561 in words is "one billion, one hundred eighty-six million, seven hundred forty-one thousand, five hundred sixty-one".