1091131840 has 56 divisors (see below), whose sum is σ = 2642341680. Its totient is φ = 429047808.

The previous prime is 1091131819. The next prime is 1091131849. The reversal of 1091131840 is 481311901.

It is a junction number, because it is equal to n+sod(n) for n = 1091131799 and 1091131808.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1091131849) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10017 + ... + 47776.

Almost surely, 2^1091131840 is an apocalyptic number.

1091131840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1091131840 is an abundant number, since it is smaller than the sum of its proper divisors (1551209840).

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

1091131840 is an equidigital number, since it uses as much as digits as its factorization.

1091131840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57869 (or 57859 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 28.

The square root of 1091131840 is about 33032.2848134972. The cubic root of 1091131840 is about 1029.4985588231.

The spelling of 1091131840 in words is "one billion, ninety-one million, one hundred thirty-one thousand, eight hundred forty".