1091423840 has 96 divisors (see below), whose sum is σ = 2923089120. Its totient is φ = 381763584.

The previous prime is 1091423833. The next prime is 1091423849. The reversal of 1091423840 is 483241901.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 1091423797 and 1091423806.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1091423849) 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, 25712 + ... + 53328.

It is an arithmetic number, because the mean of its divisors is an integer number (30448845).

Almost surely, 2^1091423840 is an apocalyptic number.

1091423840 is a gapful number since it is divisible by the number (10) 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 1091423840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1461544560).

1091423840 is an abundant number, since it is smaller than the sum of its proper divisors (1831665280).

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

1091423840 is a wasteful number, since it uses less digits than its factorization.

1091423840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27664 (or 27656 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 1091423840 is about 33036.7044361268. The cubic root of 1091423840 is about 1029.5903860299.

The spelling of 1091423840 in words is "one billion, ninety-one million, four hundred twenty-three thousand, eight hundred forty".