1091000020 has 48 divisors (see below), whose sum is σ = 2502259200. Its totient is φ = 396270720.

The previous prime is 1091000017. The next prime is 1091000021. The reversal of 1091000020 is 200001901.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1091000021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 232861 + ... + 237499.

It is an arithmetic number, because the mean of its divisors is an integer number (52130400).

Almost surely, 2^1091000020 is an apocalyptic number.

1091000020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1091000020 is an abundant number, since it is smaller than the sum of its proper divisors (1411259180).

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

1091000020 is a wasteful number, since it uses less digits than its factorization.

1091000020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5728 (or 5726 counting only the distinct ones).

The product of its (nonzero) digits is 18, while the sum is 13.

The square root of 1091000020 is about 33030.2894325799. The cubic root of 1091000020 is about 1029.4570991326.

Adding to 1091000020 its reverse (200001901), we get a palindrome (1291001921).

The spelling of 1091000020 in words is "one billion, ninety-one million, twenty", and thus it is an aban number and an uban number.