1091286780 has 96 divisors (see below), whose sum is σ = 3243421440. Its totient is φ = 273208320.

The previous prime is 1091286731. The next prime is 1091286787. The reversal of 1091286780 is 876821901.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1091286787) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 499731 + ... + 501909.

It is an arithmetic number, because the mean of its divisors is an integer number (33785640).

Almost surely, 2^1091286780 is an apocalyptic number.

1091286780 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 1091286780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1621710720).

1091286780 is an abundant number, since it is smaller than the sum of its proper divisors (2152134660).

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

1091286780 is a wasteful number, since it uses less digits than its factorization.

1091286780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2699 (or 2697 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 42.

The square root of 1091286780 is about 33034.6300115500. The cubic root of 1091286780 is about 1029.5472858884.

The spelling of 1091286780 in words is "one billion, ninety-one million, two hundred eighty-six thousand, seven hundred eighty".