1091471808 has 448 divisors, whose sum is σ = 3820290048. Its totient is φ = 267632640.

The previous prime is 1091471789. The next prime is 1091471809. The reversal of 1091471808 is 8081741901.

It is a tau number, because it is divible by the number of its divisors (448).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1091471809) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 16290591 + ... + 16290657.

Almost surely, 2^1091471808 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1091471808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1910145024).

1091471808 is an abundant number, since it is smaller than the sum of its proper divisors (2728818240).

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

1091471808 is a wasteful number, since it uses less digits than its factorization.

1091471808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160 (or 150 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 39.

The square root of 1091471808 is about 33037.4304085533. The cubic root of 1091471808 is about 1029.6054692836.

The spelling of 1091471808 in words is "one billion, ninety-one million, four hundred seventy-one thousand, eight hundred eight".