1781122266 has 144 divisors (see below), whose sum is σ = 5185814400. Its totient is φ = 435375360.

The previous prime is 1781122253. The next prime is 1781122271. The reversal of 1781122266 is 6622211871.

It is a self number, because there is not a number n which added to its sum of digits gives 1781122266.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 159535 + ... + 170333.

It is an arithmetic number, because the mean of its divisors is an integer number (36012600).

Almost surely, 2^1781122266 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1781122266, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2592907200).

1781122266 is an abundant number, since it is smaller than the sum of its proper divisors (3404692134).

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

1781122266 is a wasteful number, since it uses less digits than its factorization.

1781122266 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10849 (or 10839 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 1781122266 is about 42203.3442513742. The cubic root of 1781122266 is about 1212.1729199737.

The spelling of 1781122266 in words is "one billion, seven hundred eighty-one million, one hundred twenty-two thousand, two hundred sixty-six".