1091181856 has 96 divisors (see below), whose sum is σ = 2411156160. Its totient is φ = 483065856.

The previous prime is 1091181853. The next prime is 1091181859. The reversal of 1091181856 is 6581811901.

It is an interprime number because it is at equal distance from previous prime (1091181853) and next prime (1091181859).

It is not an unprimeable number, because it can be changed into a prime (1091181853) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1994575 + ... + 1995121.

It is an arithmetic number, because the mean of its divisors is an integer number (25116210).

Almost surely, 2^1091181856 is an apocalyptic number.

1091181856 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1091181856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1205578080).

1091181856 is an abundant number, since it is smaller than the sum of its proper divisors (1319974304).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1091181856 is a wasteful number, since it uses less digits than its factorization.

1091181856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 786 (or 778 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 40.

The square root of 1091181856 is about 33033.0418823335. The cubic root of 1091181856 is about 1029.5142888542.

The spelling of 1091181856 in words is "one billion, ninety-one million, one hundred eighty-one thousand, eight hundred fifty-six".