1091905920 has 768 divisors, whose sum is σ = 4811788800. Its totient is φ = 230916096.

The previous prime is 1091905873. The next prime is 1091905921. The reversal of 1091905920 is 295091901.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1091905921) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 18506851 + ... + 18506909.

It is an arithmetic number, because the mean of its divisors is an integer number (6265350).

Almost surely, 2^1091905920 is an apocalyptic number.

1091905920 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 1091905920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2405894400).

1091905920 is an abundant number, since it is smaller than the sum of its proper divisors (3719882880).

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

1091905920 is an equidigital number, since it uses as much as digits as its factorization.

1091905920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117 (or 93 counting only the distinct ones).

The product of its (nonzero) digits is 7290, while the sum is 36.

The square root of 1091905920 is about 33043.9997578986. Note that the first 3 decimals coincide. The cubic root of 1091905920 is about 1029.7419531403.

The spelling of 1091905920 in words is "one billion, ninety-one million, nine hundred five thousand, nine hundred twenty".