1091100020 has 12 divisors (see below), whose sum is σ = 2291310084. Its totient is φ = 436440000.

The previous prime is 1091099987. The next prime is 1091100119. The reversal of 1091100020 is 200011901.

It can be written as a sum of positive squares in 2 ways, for example, as 836250724 + 254849296 = 28918^2 + 15964^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1091099968 and 1091100004.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 27277481 + ... + 27277520.

It is an arithmetic number, because the mean of its divisors is an integer number (190942507).

Almost surely, 2^1091100020 is an apocalyptic number.

1091100020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1091100020 is an abundant number, since it is smaller than the sum of its proper divisors (1200210064).

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

1091100020 is a wasteful number, since it uses less digits than its factorization.

1091100020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54555010 (or 54555008 counting only the distinct ones).

The product of its (nonzero) digits is 18, while the sum is 14.

The square root of 1091100020 is about 33031.8031599851. The cubic root of 1091100020 is about 1029.4885511836.

Adding to 1091100020 its reverse (200011901), we get a palindrome (1291111921).

The spelling of 1091100020 in words is "one billion, ninety-one million, one hundred thousand, twenty".