1091876861 has 4 divisors (see below), whose sum is σ = 1139349792. Its totient is φ = 1044403932.

The previous prime is 1091876843. The next prime is 1091876873. The reversal of 1091876861 is 1686781901.

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 an emirpimes, since its reverse is a distinct semiprime: 1686781901 = 7 ⋅240968843.

It is a cyclic number.

It is not a de Polignac number, because 1091876861 - 2¹⁸ = 1091614717 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1091876801) 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, 23736431 + ... + 23736476.

It is an arithmetic number, because the mean of its divisors is an integer number (284837448).

Almost surely, 2^1091876861 is an apocalyptic number.

It is an amenable number.

1091876861 is a deficient number, since it is larger than the sum of its proper divisors (47472931).

1091876861 is an equidigital number, since it uses as much as digits as its factorization.

1091876861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47472930.

The product of its (nonzero) digits is 145152, while the sum is 47.

The square root of 1091876861 is about 33043.5600533599. The cubic root of 1091876861 is about 1029.7328181845.

The spelling of 1091876861 in words is "one billion, ninety-one million, eight hundred seventy-six thousand, eight hundred sixty-one".