1091820920 has 32 divisors (see below), whose sum is σ = 2601104400. Its totient is φ = 411038208.

The previous prime is 1091820871. The next prime is 1091820929. The reversal of 1091820920 is 290281901.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1091820929) 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, 802130 + ... + 803489.

Almost surely, 2^1091820920 is an apocalyptic number.

1091820920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1091820920 is an abundant number, since it is smaller than the sum of its proper divisors (1509283480).

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

1091820920 is a wasteful number, since it uses less digits than its factorization.

1091820920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1605647 (or 1605643 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 32.

The square root of 1091820920 is about 33042.7135689550. The cubic root of 1091820920 is about 1029.7152321760.

The spelling of 1091820920 in words is "one billion, ninety-one million, eight hundred twenty thousand, nine hundred twenty".